I can't even make an LED flash!

[skimask]

Nup, it's just a plain old 16f628, i thought i'd blown up the chip so I tried another and no luck either - the only thing diff that I don't normally do is use a crystal - I have a long time ago but not recently

Cheers

Another (probably bad) idea, I know your MCLR is defined as off, have you tried a pullup on it anyways?
Voltage on Vdd?
Have you let it run for more than about 10 seconds? If the LEDs are flashing at about 10 second intervals, somehow it might be getting on the internal 37khz clock instead of your 4mhz clock.