Application Error-Load Segment Failure

I developed a small db application for an online phone directory. If I run the
app from a local hard drive (where it was developed), there is no problems. If
I copy the program to a network drive (using the same configuration settings as
before), the user gets the following error approx. 25% of the time at program

                Application Error

        <progname> caused a Segment Load Failure in
        module <progname>.EXE at 0002:0632

Any ideas why?