DMA Controller in burst + Avalon MM PCIe results in data corruption.

I am having some trouble with Stratix and the DMA Controller in Burst mode and the Avalon MM PCIe bridge.

When I start a 4k byte transfer with a SRC address of 0x****_9910 and DEST address of 0x****_A910 ... where the DMA controller is performing a DDR -> DDR move in the RC, I get unpredicable results. DMA controller is set for 4k burst length and Doubleword transfers.

One failure is the last part of the DMA is not written to the desination buffer. ( see attachement )

One failure is wrong data written around the 4k boundary crossing.

If I start at address of 0x****_9900 and cross the 4k boundary the test passes .

If I start at address of 0x****_9910 and do not cross the 4k boundary the tests passes.

Does any one know if the Avalon PCIe bridge has to have certain address when a burst transfer crosses a 4k boundary ?

Thanks, Bob.

Also: I can't find the logic that performs the 4k boundary crossing ( ie splits a transaction into two transactions to avoid crossing the 4k boundary ) Could that logic reside in the Hard PCIe IP ?