Errors reading M9K dual port in Cyclone III

Can you SignalTap it and capture addresses and data in and out? How do you know it's the memory and not something elsewhere.

If it occurs when cold, it might be a hold violation. Where do your read and write clocks come from? Are you sure the data in and control is clocked on the write domain while the read data is clocked back into the read domain? (If you're not analyzing between the domains because they're asynchronous, then clocking something in the wrong domain wouldn't show up static timing analysis)