SYDNEY, Australia — Whitney Houston has hit another sour note on her Australian tour.

Fans walked out of the singer's show last night in Sydney, two days after Houston was accused of a lackluster performance in Brisbane. The backlash prompted Houston's publicist to release a statement Thursday, dismissing rumors that the 46-year-old R&B star is experiencing health problems.

''Whitney is in great health and having a terrific time on her tour and with her fans," rep Kristen Foster said. ''Her fans were dancing and singing along with her and Whitney appreciates their support.''

But not everyone is saying "I Will Always Love You."

"It's the worst concert I've ever been to in my entire life," one disgruntled fan told CBS News of the Brisbane show.

"She couldn't entertain a dead rat," added another disappointed concertgoer.

Houston next performs Saturday at the Hope Estate Winery, where many fans have been calling to ask for refunds and express concerns about the show.

"Yeah, we've had a lot of calls from people ringing up to have a whinge," a spokeswoman for the Hunter Valley venue told Sydney's Daily Telegraph. "They've been asking if the concert is still going ahead, and, if it does, whether she'll make it back to the stage if she has a break. But the show is going ahead - there seems to be an overreaction out there."

The "Nothing But Love Tour" is the singer's first Australian concert trek in 22 years.

Watch video from last night's show in Sydney: