Robert,
Your modal forms appear to be doing something to alter the the environment, like changing the PATH or current directory. If they both launch ok, it sounds like they are disrupting things when they close. You are going to have to step through the code in the debugger to track down the error in the code.
>I have a form that launches two other modal forms . The first time , they launch fine . But the second time , it says that the form cannot be found . Apparently it does not search in the path specified with SET PATH. Any thoughts on this?