Opacity: 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 invis : )
Apparently http://code.google.com/p/chromium/issues/detail?id=559
Note: Due to the sensitive nature of the data in our tracking system, no public list of known bugs is available.