Solution:
Step 1. On your BFBC2 exe file, right click. Select 'Properties' and got to 'Compatibility' Tab
Step 2. Check the 'Disable Desktop Composition' and 'Disable visual themes' Boxes
== No more popups / no more error
Thanks Arithon, will give that a try.
But I'm not holding my breath as it has crashed back to desktop many times but I've only had the popup once. For me, it only happens on our server on White Pass (which is the 650 ticket conquest map). Personally i think my PC (as some players have also said) get's board of such a long battle.
Is there a way for this to be done via the steam game launch settings box?
As i don't really want to have to make a desktop shortcut to solve the issue.