IDC not working and U2 programmer issues

[queenidog]

I have two problems. First the background. I'm using PBP3.0 with Mechanique Microcode Studio Plus. I wrote for the 16F887 on my Lab x1 development system ran the IDC, got all the bugs out, program works.

I recompiled for the target MCU, a 16F628a, changing the pins as necessary and adding config fuse to use the internal oscillator.

Problem #1: "some times" when I try to program the 16F628a using the U2 programmer, I get a message "Lost communication with programmer". This I assume is on the USB side so why should it work sometimes, and other times not? I can't get it to work when I want. Sometimes I'll just keep hitting the program button, then all of a sudden it will kick off and work. I NEVER had the problem when connecting on the programming side to the LabX-1 but have this problem when I connect to my 16F628a chip.

Problem#2: I take the 16F628a chip out of it's socket and put it into an MeLabs Zif converter. I don't get the "lost communication" error (this time using the supplied 10 conductor ribbon cable). It programs fine, every time.
However, when I program for the ICD, and RUN the ICD, I get "ICD connection timeout". I'm using a Max232 chip to convert my serial signals from my computer to the chip. I'm supplying 5VDC to the chip and the Max232, of course.

I'm using the default internal 4 MHz oscillator.

I have read about Problem #1 through a Google search, but it was an old problem and no solutions were proposed.

[queenidog]

I fixed problem #1 and it is strange. There are 4 connections between my 16F628a and the U2 programmer. With the GROUND connection hooked up, I get the error and no download. With the ground connection DISCONNECTED, I don't get the error and I can program the MCU everytime! Just to be clear, I have a 5 volt power supply to my circuit containing the 16F628a, and my U2 programmer connected by USB only without the ground wire connected in anyway to my circuit or power supply. Hey, it works! I checked lines with a meter and scope and see nothing wrong (no shorts, opens, noise issues).

On to #2 problem.