I use a USB to serial adaptor with the EAS software running under XP. I purchased the adaptor from Maplin, it came with a driver and worked first time. Vista is known to have problems with some USB to serial adaptors (not to mention lots of other device drivers), but I still wonder if it is a sync problem that you have.
You must have the patience of a saint with what you have had to put up with with your P38, your missus can't be over the moon with it either. I'm sure you will get there in the end, persistance overcomes all eventually.