I was wondering if anyone could help me with this, I received my 680 (PYN VCGGTX680XPB-CG) yesterday and attempted to flash it using NVFlash 188.8.131.52 in windows XP. First of all the ROM I downloaded was a BIN file which I thought I could just rename to .ROM but NVFlash didn't like it and would still throw an I/O error. I then used Nibitor bio editor to import the BIN file and save it as a ROM file, so now I have a usable file. I then proceeded to flash the card with the said ROM and NVFlash reported a successful flash so I restarted my MP and I had boot screens! but when trying to get into OSX (10.8.3) It would just hang on the apple logo with the loading wheel and reboot but there isn't a problem getting back into Windows XP, does any one have any ideas of what's going on? I used the card to play a few hours worth of gaming before doing the flash and it was fine and again after I put the stock ROM back on and there aren't any artefacts or anything strange. Any help would be much appreciated. EDIT: I forgot to mention my Mac Pro is a 2009 8 core 2.26Ghz model.