Hardware not working as intended

Comparing "size_t" with "unsigned int" could cause problems since the size of "size_t" is implementation-dependent. Though if that was to cause problems, I would also expect it to show up in emulation. Either way, you can try defining both variables in the same way, or casting one to another and see if it fixes your problem. Still, I have never seen a standard kernel with no channels deadlock. You can also try different versions of Altera's compiler to see if you get different behavior. If you could still reproduce the problem with the latest version of the compiler, I recommend reporting it to Altera; it might as well be a compiler bug.