Clearing McBSP interrupts...

Does anybody have any experience with interrupt-based I/O on the McBSP
ports? I think that I've set the port up correctly, as I do get
(mostly) proper output, but I cannot seem to clear the interrupt flags
in the IRQSTATUS register while in my ISR. I've tried writing ones to
the flagged and enabled interrupts (I read the IRQSTATUS register,
mask off the disabled interrupts using the IRQENABLE register, and
write the result back to IRQSTATUS), but when I check the results, the
interrupts are still flagged. I've also tried writing zeros to the
triggered interrupts, with the same result. Any thoughts?

- Pat