Hi,
As a first way of debug, I would define the absolute path of the AVI file, using GetProjectDir() and MakePathName().
I've always been using these two functions when I ha ve to read data file. They prevent from having path access problems.
Hope this helps,
Ph. Joatton
int GetProjectDir (char directoryName[]);
void MakePathname (char directoryName[], char fileName[], char pathName[]);