Did you go to
http://www.irseesoft.de/tp_faqs.htm and use the patch that is supposed to fix problems with OS 3.5?
If not, you can check Aminet. I think there was a driver recently posted on there, not sure which Epson printer they support.
I've used TP 7.20 on OS 3.5 and OS 3.9 and both with an Epson Color Stylus 800 and C80 with no problems.
