Troubleshooting an ATMega328p clock setting
That's a really odd response you're seeing.  Of course there's the obvious suggestion of: have you tried power cycling everything in the chain? (PC->STK200->devboard)  But also, do you have another AVR programmer you can try?  Do you have another ATmega328P you can try reading &amp; writing?  Have you ever been able to read fuse settings with any programmer?

Other things to try:
Can you remove the crystal and see if you can communicate with the chip then?
Does your programmer have the ability to adjust SCK speed?  (the STK500 can do this, not sure about STK200)  It may be the chip got in a really low speed mode.

As a last resort, you'll need to put the chip in a high-voltage programmer.  I know at least the STK500 can do that, and there are a few circuits out there for hacking a HVP out of an Arduino or LPT port.  I've had to resuscitate a few AVR chips that way because of an electrical glitch or I flubbed settings.