I have 3 questions about this.
Have you programmed any other EPROMs or other chips in the programmer, and verified that it works after your tried the 2732s?
Have you selected the correct EPROM type in the programmer? The 2732A is a NMOS chip and I would think it requires a high voltage Vpp.
Have you successfully programmed any M2732A EPROMs in this programmer?
You have socketed the EPROMs correctly in the programmer?
BTW I always use at least 30 mins erase time, since most UV lamps are getting older, and so are the EPROMs.