flash programmer - payload buffer

Same problems here. We use speed grade 8, although I don't know if that's the problem. I went through several iterations with mk_target_board using different clocks (above and below 50MHz) and different payload buffers. It seems that smaller payload buffers work better but I don't think that's the whole story. It seems to be a combination of host USB, PC speed and payload buffer. Generally speaking, there seems to be some kind of synch problem between the USB blaster and the Cyclone. I can't get it to work on my USB hub but it does work with the built-in port. I also couldn't get big payload buffers to work at all. Luckily we have piles of different PCs in every cube so we can find a combination that works.