It sounds like you were getting the same problem as I was. Looks like you have now fixed it. If you still have your JDM type programmer, could you download the software from Here and try it to see if it fixes your serial problems. You may also find it works well with your new circuit as well.
I already use WinPIC and I was having problems with the JDM for both WinPIC and ICProg as well. With the new programmer, it works great with both pieces of software and all of my chips. I think the problem with my JDM was lack of current on the COM port. I don't think VPP was rising fast enough to put the chip into programming mode. The NOPPP has it's own power supply so this isn't a problem any more.