To the OP, use a USB programmer, regardless.
History has a way of repeating itself. AVR's, PIC's doesn't matter, neither are immune to RS232 port programmers working in a modern world. For instance, problems relating to the DIY JDM PIC programmer posts abound on the forum, works for some or most, others not. And yes it can be related to the user host device, and/or interface cable as you have mentioned. I would suggest to nip any frustration at the bud, by eliminating these variables.