depends which pin it was. sometimes a simple u-wire will work.
Putting an 800 fsb cpu into a motherboard that does not support that bus speed will sometimes result in the CPU posting with a 400 fsb. Other time it will just fail to post at all. I've seen it both ways.
The reason for the revision is most likely for prescott support, which I would surmise your chipset does not have. That prescott CPU may not work in either of the motherboards, not due to bus speed issues, but instead due to chipset limitations and VRM issues.
also is it possible to fix a broken processor pin?
Not if it's actually broken. BUT if you're lucky it may be one of the very many redundant ground pins - if it is it probably won't matter if it's broken.
You can download the pinout diagram of the CPU from this page on the Intel website to see which pin you've broken. Look in section 4 ("Land Listing and Signal Descriptions") - pins marked "Vss" are the ground pins and you can probably run without one of them. Pins marked "Vcc" are positive power supply pins, and there's a good chance you can run without one of those as well.
Note that there is no pin at position A-1 on the pinout diagram - that should help you orient the diagram to match your CPU.