If you Jalibreak your PS3 and then install a modded patch and then update the PS3 FIRMWARE then no, the patch that you put on for that game will stay there untill a new game update, say for MW2, then it would overwrite your old patch. But, you do this at the cost oflosing your ability to Jailbreak your PS3. In my eyes, there is no point in losing you Jailbreak for a couple of chrome guns, better stats, challenges etc. Just wait, a better solution will soon appear.