(CNN) -- First it was Triumph, then Elation, Dream and now Legend.

While they are happy names for cruise ships, some passengers say they've had experiences recently that belie those names.

In yet another setback, Carnival Cruise ship Legend is having technical difficulties that are affecting its sailing speed, the latest in a growing list of woes for the travel company.

The Legend was on the last leg of a seven-day Caribbean cruise that departed Tampa on Sunday. Within a span of a month, three other Carnival Cruise ships have reported problems.

Carnival Elation had to be escorted by a tugboat Saturday because of a malfunction in its steering system, the cruise company said.

And in the most publicized case, last month, an engine room fire left the Carnival Triumph crippled and adrift in the Gulf of Mexico with more than 4,200 people aboard. That scheduled four-day cruise stretched into eight days as tugs pulled the vessel into port in Alabama. Food was scarce and passengers sweltered in the heat with no air conditioning.

Because of the problems on the Legend, Carnival said it had canceled a scheduled stop in Grand Cayman and the ship will make its trek back to its scheduled ending destination in Tampa, Florida.

Even though the vessel is expected to arrive on schedule Sunday, some are losing patience, passenger Rob Bonenfant said.

"Passengers are now really pissed off," Bonenfant said via e-mail. "Mood on the ship is getting worse among passengers, captain is giving limited information."

Carnival has promised to refund $100 to passengers and give them other refunds and discounts.

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"Carnival Legend is experiencing a technical issue with one of the ship's Azipod units that is affecting the vessel's sailing speed," the cruise company said. "The ship's safety systems and hotel services are all functioning normally."

The Azipod, a crucial part for steering and propelling a vessel, was the same issue that hampered the Carnival Elation on Saturday.

Some passengers on Carnival's stricken cruise ship Dream are also complaining.

Although power has been restored and facilities were functioning again, passengers still have to be flown back to Florida after the ship malfunctioned in the eastern Caribbean.

Cruise passengers received a letter from the captain, according to a passenger who e-mailed a photo of the correspondence to CNN.

Capt. Massimo Marino told passengers they will be booked on flights to Orlando or another destination. Passengers with cars at Port Canaveral will be bused from Orlando to the facility about an hour away.

The letter also offers passengers a three-day refund and a half-price cruise in the future.

The captain said passengers could "enjoy another day in beautiful St. Maarten" or stay onboard for a "full schedule" of activities.

"We sincerely apologize for the disappointment this unexpected change has caused and regret we were unable to provide you with the fun and memorable cruise vacation we had in store for you," he wrote.

In a statement, Carnival said the ship's emergency diesel generator failed. The ship's next voyage was canceled, the cruise line said.

Carnival spokesman Vance Gulliksen said Thursday that 4,300 guests were aboard the Dream along with about 1,300 crew members. Carnival's website puts the ship's capacity at 3,646 passengers, but that's based on only two people per cabin, and some cabins hold more, Gulliksen explained.

There are also three- and four-person cabins aboard.

The first flights for passengers stranded on cruise ship Dream will begin Friday at 9 a.m. ET., starting the process of 10 flights expected to take 2,184 passengers back home Friday, Carnival said. More passengers will be taken on the weekend.

On Tuesday, Carnival announced it was conducting "a comprehensive review" of all of its 23 ships after a fire last month that crippled one of its ships in the Gulf of Mexico, leaving passengers stranded for days while the vessel was towed back to land. Carnival President and CEO Gerry Cahill said the probe will focus on the prevention, detection and suppression of fires, engine room redundancies, and what additional hotel facilities might be provided and might run off the emergency generators.

After the problems began Wednesday, CNN was contacted by passengers describing the conditions.

Gregg Stark, who is traveling with his wife and two young children, said the conditions are deplorable.

"There's human waste all over the floor in some of the bathrooms and they're overflowing -- and in the state rooms," Stark said. "The elevators have not been working. They've been turning them on and off, on and off."

An announcement over the ship's public address system said the crew was trying to fix the problem and was working on the generators, according to Stark. A few hours later, another announcement said the problem was worse than originally believed.

"We are not allowed off of the boat despite the fact that we have no way to use the restrooms onboard," Jonathan Evans of Reidsville, North Carolina, said in an e-mail Thursday. "The cruise director is giving passengers very limited information and tons of empty promises. What was supposed to take an hour has turned into 7-plus hours."

But Thursday afternoon, Carnival told CNN that based on conversations with the ship's management team, a look at service logs "and extensive physical monitoring of all public areas, including restrooms, throughout the night, we can confirm that only one public restroom was taken offline for cleaning based on toilet overflow and there was a total of one request for cleaning of a guest cabin bathroom.

"Aside from that, there have been no reports of issues onboard with overflowing toilets or sewage. The toilet system had periodic interruptions yesterday evening and was fully restored at approximately 12:30 a.m. this morning."

Last month, an engine room fire left the Carnival Triumph crippled and adrift in the Gulf of Mexico with more than 4,200 people aboard.

That scheduled four-day cruise stretched into eight days as tugs pulled the vessel into port in Alabama. Food was scarce, and passengers sweltered in the heat with no air conditioning. People aboard also reported overflowing toilets and human waste running down the walls in some parts of the ship.

A class action lawsuit was filed against Carnival Corp. in the aftermath.

The Triumph is still undergoing repair at a shipyard in Mobile, Alabama, Carnival spokeswoman Joyce Oliva said.

"We are now focused on the lessons we can learn from the incident and also what additional operational redundancies might be available," Cahill said this week.

Another ship, the Carnival Splendor, had a fire in 2010 due to "a catastrophic failure of a diesel generator," said Cahill, the Carnival president.

Sen. Jay Rockefeller, the chairman of the Commerce, Science and Transportation Committee, sent a letter Wednesday to Micky Arison, the chief executive officer of Carnival Corp.

"The Coast Guard has responded to a string of 90 marine casualty incidents with passengers onboard Carnival ships in the last five years," the West Virginia Democrat wrote. "It seems that Carnival has failed to take any meaningful course of corrective action after these continual incidents. This needs to change."