I suspect that mod_perl is a red herring. Try it with a regular CGI and see what happens.
One guess is that the issue is in how you are doing the pop-up. You can test that by trying to make it a regular link.
Another is that it is a bug in your script where you think that a parameter is being passed but it is being dropped somewhere. Do the usual use strict routine.
If you still cannot find it, it would probably be helpful if you tried posting code... |