I have found 3 Great fixes ,Xfire related, in BC2 from Triple Deuces Clan I am a part of.
First I tested a suggestion from some one here (cant find the post) do readjust your resolution.
If you get flickering on weapons and water, hit escape , options , resolutions, and click the same resolution you are already running and its goes away perfect.
Now catalyst AI run on normal settings and accelerates multiple card frames rates without
normal glitches and bugs. Thanks to whomever was original poster.
Second this post eliminated all my crashes. 50 rounds crash free.
The original poster said it would fix gray screen issues (which AFAIK is a 2d ongoing ATI prob)
Got this today from a friend, I'd heard of this method before but wasn't sure until I saw this forum post giving a step by step....it's actually a VERY easy fix.
http://www.overclock.net/ati/641299-guide-...fterburner.html
Steps for those too lazy to visit the link;
DL a program called MSIafterburner (I used version 1.4.1)
Find the MSIafterburner folder on your PC, open it up and find MSIafterburner.cfg and open that file with notepad.
Go to the bottom line of text "EnableUnofficialOverclocking" and change the value from a 0 to a 1.
Save as (all file types) same file name as it had, YES to overwrite original file.
Restart Afterburner and adjust your clock speeds to whatever speeds you want, in my case I went with pretty close to stock speeds.
Save those settings as profile 1
Hit reset and then save the reset settings as profile 2. This will allow you to do non-gaming stuff without having your clock speeds at the 3d clocks.
You'll have to make sure to go into afterburner and hit 1 and apply and you should be all set..
I did this tonight and I was able to play BC2 all night without a single crash. I'm stoked as shit about this obviously because before I couldn't play more than 10 or 15 minutes before I'd crash....I'm also playing it with all settings as high as they go, 1920x1200 8xAA, 16xAF without any noticeable choppiness. I haven't really paid attention to performance so far but every time I looked at fraps I was at or above 70fps. So I'm happy as shit right now 8) 8)
Lastly I dont have this problem but many people do
Some Mouse tweeks:
Removing Mouse Acceleration for Win 7 and Vista/XP
Just what it says. There is no way to get rid of acceleration otherwise that I can find. Win 7 only lets you slow down the acceleration at most. This gives you an exact 1 to 1 ratio to your screen. I have tried this one and it works great. It becomes much easier to keep your cross hairs on somebody. The link also lists fixes for Vista/XP.
Note: This is a global fix and affects everything, so if you need to keep mouse accleration for other things you may want to look elsewhere. Or at least back up your registry.
http://www.esreality.com/?a=post&id=1846538
It supposedly gets rid ot the mouse smoothing and helps speed up turret movement and helicopter response some. There is apparently a hard code to how much you can increase it.
Removing mouse smoothing and increasing turret speed
http://forums.penny-arcade.com/showthread....95#post13997695 (It's about 1/3 way down the page, posted by Carbonfire)
I would just copy and paste but there are a lot of pictures as well.
Game on ... (with war tapes)
That was some intence stuff, thanks goes to rest of the squad.
Doesn't even matter that sometimes ping is just too much to win those 1vs1. Not to mention I get knifed a lot, I sort of see a correlation on how well a round has went to if a person shoots or knifes me 
