Your second X Server wasn't using DRI, though you seem to suggest that it was somehow. Compiz apparently doesn't do well with the software rasterizer, which isn't surprising.
With KMS and the current driver, thanks to Dave Airlie, you'll get multiple servers with DRI support. Unless you intend this bug to be about software rasterizer issues with compiz, I think this is RESOLVED -> FIXED now.
Your second X Server wasn't using DRI, though you seem to suggest that it was somehow. Compiz apparently doesn't do well with the software rasterizer, which isn't surprising.
With KMS and the current driver, thanks to Dave Airlie, you'll get multiple servers with DRI support. Unless you intend this bug to be about software rasterizer issues with compiz, I think this is RESOLVED -> FIXED now.