I had the same problem with my power supply. It to was too high voltage.
The power supply eventually died on me... when I got another one everything
was ok.

You get get new psu's for free if you contact Microchip.

I also recommend that you also upgrade your programmer to the latest firmware
version.
(Latest MP-LAB sometimes has trouble communicating with older PICStart
firmware).

Hope this helps.
    Regards,
    Darren Logan BSc