Hi,
Try to set the download source of PPM from this link instead:

http://www.bribes.org/perl/ppm/
http://www.apache.org/dyn/closer.cgi/perl/win32-bin/ppms/

I wonder what version of Perl are you using?
Try Perl 5.8 above, if you are still using 5.6. There known to be a problem with DBD::mysql when used with 5.6
Hope that helps