Why does Mandalay Bay in Las Vegas have a terrible odor in their ventilation system? I?

I've visited Mandalay Bay many times since they opened in 1999 and was a guest there in 2008. I've never encountered any unpleasant odors there.

I have seen complaints online about the "air freshener" aroma that's used at Palazzo though.

Mandalay Bay is owned by MGM Mirage, so if they've started using "air freshener" I'd expect that policy to be applied to all of their properties (Monte Carlo, Bellagio, MGM Grand, Mirage, Aria, Vdara, Circus Circus, New York New York, Excalibur, Luxor.)

I shot this photo from the Luxor parking lot in1998 or 1999:

http://www.urbanphotos.net/images/LVCD/slides/mand...

Then this one from the 30th floor of Luxor in 2006:

http://www.urbanphotos.net/images/las_vegas_5/slid...

I stayed at the Luxor and of course went to Mandalay Bay every day. I never noticed any foul smell at all.

Perhaps it is the smell of all that dirty money?

Never had a problem with odor there