Hi folks ! First, there is my Specs : 10.6.4 MBP Penryn 2,5Ghz, 4Gb RAM, 8600M GT 512Mb, and a 320Gb Seagate Momentus (7200rpm) I got stuck with a little but VERY annoying problem since Snow Leopard everything is running fine, but I have Finder graphical glitches and Spaces glitches/Lag too For instance, When I open a new window from a folder for the first time (for each folder), I have a glitch appearing, i can see one or two frames of the popping window animation. Another example is Space lagging when I am switching in Fullscreen mode sometimes, and often showing graphical glitches while I am moving a window in Spaces+Exposé mode. These are minors bugs BUT there has been no updates on this since 10.6.0 through 10.6.4, and I tried these on Fresh Leopard and Fresh Snow Leopard systems on an external HD (7200rpm with FW800). Results are evident : Snow Leopard is causing this. So, because Apple can't respond (one guy tried on the Support communities forums at Apple.com/Support, and I spammed them with the Mac OS X feedback between 10.6.3 and 10.6.4), and because I am now sure this is just a problem between Snow Leopard and the 8600M GT driver I am looking for other persons earning a Penryn MacBook Pro with this same graphic card to locate precisely the problem. Is there some people here with a MBP Penryn and 10.6 ?