Yeah, sounds like it's hosed. Do you get the Splash screen or any text before it reboots?
If so, at least the boot-loader works. Then it would likely be crashing in the WinCE or the Pioneer application. So you might be able to install the CNSD-210FM upgrade by first booting an SD with the ShortFuse 2.004 Hack. If that loads, just proceed with the CNSD-210BT upgrade. As long as the corrupted files are part of the upgrade, you should be good.
Otherwise, your only recourse is to try booting into TestMode. From there you may be able to restore from the backup partition. From the factory, there are 2 identical program partitions (NAND/PRG0 & NAND/PRG1). I believe the updates only write to the 1st one. Sorry, I have never done this, so I can't walk you through. Search around for the forums for the term testmode and you should find some info. If you find someone who seems to know what their talking about (i.e. not Me) then you might PM them to ask for help.
If you can't get into testmode, you'll just have to send the unit in for repair. It'll cost a couple hundred $$$ because I doubt any warranty would cover problems loading bootleg software.
Good luck. BTW, it hasn't been pointed out in a long time, but as a warning to others - ALWAYS load updates with the ignition in the Accessory position. If your car battery is weak, also use a charger to keep it from draining. An alternative would be to do it with the engine running (outside).
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