Need help testing my web app. Its bombing on some computers and I don't know why

The title says it all. Below is a link to my project that I am trying to get ready to launch. It is starting to work pretty well for me, but its bombed on a few people.:worried: So far it seems to be older Macs, but i really have no idea. Maybe something to do with Intel based vs. the other. The only other thing I can think of that may cause a problem, is when I get a list of system fonts from the computer, but not sure if that would cause any problems or not.

Anyway, I could really use some help testing this out. I am unable to replicate the problem on any of my computers. Thanks for any help you may offer.

~squirt

here is a link to my site. www.drawzit.com