ATi has released ATI Catalyst™ 10.4 Hotfix for series 5 graphics cards (series 4 graphics cards are expected to get the drivers next week). You can read more about the driver hotfix at AMD.com.
ATI Catalyst™ 10.4 Preview features: The ATI Catalyst 10.4 Preview provides resolution for the following issue:
Long load times for new maps in Battlefield: Bad Company 2 when using an ATI Radeon HD 5xxx series graphics card
Note! This driver is provided as is and is not supported by AMD. It has not completed full AMD testing, and is only recommended for users experiencing the particular issue described above. This release is not supported by ATI Radeon™ HD5800 Eyefinity 6 series of products.