Nios locks up with data cache bursts enabled

Update:

Using SignalTap, I can see that the reason the Nios is locking up is because it is waiting indefinitely for the Avalon read instruction to complete. The Nios data_master port is issuing a read, but the wait_request signal is never going low. On the slave side, however, the Avalon read signal is never going high. So something in the auto-generated interconnect appears to be indefinitely stalling the read.