It does, there's a problem with the lift off distance and the laser switching itself off. I'm a low sens player and when I tried lifting my mouse off the mat and replacing it'd take a split second to do anything. Added onto the fact that when you do place it back down it'll jump to the bottom right slightly. The sensor on it is just plain crap.
It's basically a wireless Deathadder with a few difference, most of them aren't good ones. I have both a Mamba and a Deathadder sitting here and there's a reason why I use the Deathadder for gaming and the Mamba just to impress my console buddies.
All in all, don't waste time/money on a Mamba, or any gaming mouse costing more than £40 or so. Most people that take games seriously stick to MX518/G400/Deathadder/Xai (Although the Xai has 5% hardware acceleration that can't be disabled).
I'm trying it on mine and it does not switch off - have they fixed the issue with some firmware?