pic 18f2550 programming problem

[thatonemorekid]

hi there.

i am trying to build megadrum using "latest schematics v2.7" (not synthex) but i am having trouble programming the PIC.
using WinPIC800, it can't write to PIC, firing up following error, and regular Win Pic hangs while programming.
what could be my problem?

btw: no errors on icsp & usb connectors, pin 1 of PIC reads +5V while USB connected.
selected JDM programmer in winpic800.
I don't have a serial port, so I'm using a USB/Serial adapter.
i think it's not faulty, because i can program my satellite TV receiver with the same adapter.

[dmitri]

I presume the wiring of the ISCP cable is right. Can you try it on a PC with a standard serial port?