Thanks for all, The answer is actually trying to access out of bounds of a variable - it should give access violation but in Windows it allocates a litle more space then you have requested (duplicates of four i guess). the proplem is with the read routine that seems nearly perfect, I found the error when I tried to free the variable. It actually gave me error at that time (before I forgot to free them:) ). It is very interesting not to get an error on Windows. As Mike said it is actually Access Violation. Thanks for all May the bug killer be with you... Cem Kalyoncu