For those affected, shortly after the ATI Catalyst 10.5 release, ATI issued a hotfix driver specifically for Battlefield Bad Company 2 for radeoN HD 3000 / 4000 series users. This fix should solve long load times:
The ATI Catalyst 10.5a Hotfix provides resolution for the following issue:
* Battlefield: Bad Company 2 - Long load times for new maps when using a Windows
