I can't figure this one out.

I'm using a 16F676 with a simple blinking LED program.

Here is my code:

@ DEVICE PIC16F676, INTRC_OSC_NOCLKOUT,WDT_ON, PWRT_OFF, MCLR_OFF, BOD_ON,PROTECT_OFF

TRISA = %00000000
TRISC = %00000000
ANSEL = %00000000
WPUA = %00000000

START:
HIGH PORTC.4
PAUSE 1000
LOW PORTC.4
PAUSE 1OOO
GOTO START

Ok, so I program the chip and all works well. Then I adjust the code and I try to program it again after I modify the code (increasing the pause to pause 2000). Then part of the way through the programming it gives me a configuration error during programming. It fails the programming and then when I go to compile it again, it tells me that the target does not match the device or something like that and I can never program it again. However, the code works fine so I know the PIC is intact but I just can't program it again.

So, I change to a brand new chip and complete the process over again only to get the exact same results. I've done this with 10 chips and it's all the same.

What the heck is going on here??!! I've been using PIC's for the better part of four years and I've never had this problem. I tried two different versions of MELABS programmer but I still get the same thing. I'm using PBP 2.50 and MELABS programmer 4.01. I'm also using the ICSP as I've done many times before.

Any ideas?