Here is a link for a yahoo group for zoomtext. I find these groups helpful if you have a question or are having problems that techinal support cannot answer. Then other people on the list might be able to help Thought I would list it in case your dad is interested.
http://groups.yahoo.com/group/zoomtext/
I think they have these groups for most programs because they have them for jaws also.
Ripplegirl99