0509 or 0512 should've had the 14x in there too for the 650, but anyway...
That error is not a bad flash...it's a problem with mem or the OC. I get it once in a while too, usually when I am trying to find minimum stable Vc or Vddr for a clock. If you shut down, wait a few seconds and reboot, it should recover and give you an OC error, Press F1 for setup, F2 for defaults. Just hit F1, make any changes you need to (more Vc, lower FSB, mem dividers, etc.), save and let it reboot...should be fine.
270FSB is about the norm before things get hairy on the 600s without a "real' LockFree (04B spec procs/115W = 660-670). Using SpeedStep to get 14x is not the answer everyone thinks it is, since you are still booting a default multi until 14x kicks in. So 270FSB x 17 on that 650 = 4.6GHz that it's booting at. Your best chance for decent OC at 14x is to boot BIOS at a lower/stable FSB and then use AIB or SetFSB (<- only works on BIOS 0304) to increase the clock once you are on the desktop and at a solid 14x multi. Make sure your mem divider is set appropriately to handle whatever FSB you'll get to overall. Your best bet is to start with 1:1 and work on the max clock and then get back and play with mem.