I've a big problem running programs in programming languages which need ./ to be executed (C, C++, Pascal and others) and I've really tried everything to solve it, including changing permissions on the files. This problem arose seven months ago.
I can't really explain why and how it appeared out of the blue: the day before I could run the programs, the next day no. I've no problems running programs in languages which don't need ./. I've asked some friends of mine who study computer science but neither them have found the problem.