Listview problem

I have a listview that lists off the registered contacts for a certain event. On my computer (winxp), my friends laptop (xp), his computer(xp), my clients laptop (xp), my school's computers (win2000) the program runs as expected.

However on my client's assistants' computers they don't work (WinNT and Win2000). It does not generate an error but it seems to just run over the code as if it didn't exist.

I should also mention the fact that every other listview seems to be working as expected. Only difference as far as I can tell is that this one has checkboxes.

No idea, but you might want to try some error trapping that could be placed in the listbox code to help debug when it is run to see what is going on.