Whitney Houston Whitney Houston

You can't accuse Whitney Houston of being in denial.

Two weeks after mangling "I Will Always Love You" in Birmingham, Houston croaked her way through a hoarse rendition of her signature hit at London's O2 Arena Sunday that ended with her trying to explain her vocal failings.

"She don't want to come, my soprano friend," Houston told the crowd following the raspy performance. "Sometimes the old girl sings, but not tonight. I want to do it, but she doesn't want to. ... She's getting a little... temperamental, even."

Whitney Houston, we have a problem

Her soprano friend was being uncooperative, Houston said, because of the air-conditioning — or "air-con" — in the stadium. The 46-year-old, who's making a comeback after a battle with drug addiction and her divorce from Bobby Brown, asked that it be turned off. "I can feel it — it takes away my soprano," she said.Some fans weren't taking any excuses from Houston, who paused during songs to catch her breath. Hundreds walked out of the sold-out show, according to USA Today.

Watch Houston's performance: