Nios II hanging/crashing on PIO write?

Thanks BadOmen, I think I sorted it out anyway. As my PIO out was running with a 50kHz pll clock, compared to my 50MHz system clock, I think the system was probably waiting for 1000 iterations before it wrote the data (would explain why the first one was output fine, as the two clocks would then have been in sync). I've since amended the system to both run off the same clock and the data is output fine. Although, I have a horrible feeling that I'm gonna get a 1000x repetition of each of the values I'm trying to read...