I am having this issue where the pop-up list box is fine for 1/2 of the users. The other 1/2 of the users only see about 1/3 of the pop up material.

Any suggestions?

You don't say whether your users have FMP or they're using the web, but I had this problem with the latter.

I have not fully resolved it but it seems some Internet Explorer users are seeing cached pages, so the pop-up lists are not up to date. In such cases the user doesn't seem able to reload an up to date page. Current workaround is to use Netscape or try another day -)