A couple of Q's.
How are you doing the programming? The windows control program or Alt-Ctrl-P with notepad?
How old is your mini-PAC?
Is the jumpers on the mini-PAC set to ROM or Alt?
I had alot of problems reprogramming the mini-pac. The one way I got it to work welll we using the following setup.
Set Jumper to Alt.
Use the Alt-Ctrl-P method to program.
It works like a charm.