From the Ultimarc website:
Problem: Cannot program. Utility hangs at end of programming.
If you are using the PS/2 connection, and do not have any USB keyboard on your PC, you will need to check that in the PC BIOS, "USB keyboard support" or "Legacy USB Support" is DISABLED, otherwise WinIPAC will not program properly.
Another cause of this is having non-switch items connected to inputs. In general, the inputs must be "open" (ie no switch pressed) for programming to work. This may not be the case if you have other things connected such as a game board connected at the same time as the I-PAC. Email for further advice on this if you must have other devices connected as there are workarounds.
Try that and see if it helps.