Adobe have just released an update for Adobe Premiere Pro CS5 which improves the program and adds support for some new graphic cards.  If you are connected to the internet then it may install automatically.  This is fine if you are just using Adobe Premiere Pro with no extra hardware, however, if using a Matrox MXO2 you should not to install the 5.0.2 update and wait for some updated drivers for the Matrox card before installing the new patch. 
We expect the update from Matrox in the next few weeks.