Just to let you all know I made a post reguarding slowdown in gaming due to the SP1. You can read it here:
http://www.alliedassault.com/phpBB2/vie ... p?t=145743
Also, to add to this, I read something on the BF1942 forums about you have to change a setting in BIOS reguarding the AGP aperature in order to play the game if you cannot load it, after installing SP1. I would do some research before fooling with BIOS, tho.