Have your resolved this?
You can isolate the GPUs that will run by using "-g"
since it seems like gpu 0 is hosed, try this: "-g 1,2"
this will give you gpus 1 and 2, but not 0.
Good Luck! I'm still trying to figure out a multipool setup with the config file and windows also.
Haven't resolved it, i'll give that a shot.
IIRC, sdk 2.1 wont work with your 6870, only 67xx or lower.
I have 2.1 Kernel (2.3) and 2.4 Kernel (2.6) installed, both show up in GUIminer, the 2.1 Kernel actually gives me much faster MH/s per GPU than the new kernel (Using Phoenix Miner)