Thanks to all for their suggestions..

Yes, it was recursion.

In my program, I called a subroutine inside the program with the same name as the final exe.

i.e. the prg was ziptest.prg and the subroutine was zipper. When the project compiled it created an exe called zipper.exe.

When the program ran, it came to the line calling itself.

So dona name your procedures with the same name as the exe that gets created. <vbg>

Sigh,
Mike