We have recently identified an issue under which BitsyX systems can lock up under high interrupt traffic on the SA-1111. You can read more about this issue at topic 884.
While we haven't yet reproduced the issue running Linux (eat your heart out! so far it happens only under CE), we have created a patch that takes advantage of the improved interrupt routing.
The kernel detects if the firmware has been updated to support the rework, so you can apply this patch to your kernel and it will run on boards with or without the rework. However, the patch will have no effect on boards that have not been reworked.