Germain;
One thing you can try is to reduce the rate of your application and see if that solves the problem. I'm saying that because since that board of yours doesn't have a big on board memory, it relies at the DMA data transfer very often, becoming system dependent. Try that out, and if that is the problem you will need either to reduce the rate of the task or work with the 6534 board which has a 32Mbytes on board memory.
Hope this helps.
Filipe