I also ran across this. The cause appears to be modules were installed into C:\Perl\installdir, and my path at the time of the install as c:\perl\installdir. I made the two (PATH and the actual directory name) the same, removed site, and reinstalled my packages, and voila, all is well with the world.

Note that I did not start noticing this until _after_ I installed a module and reopened ppm-shell. Does not mean that it didn't have an issue, just that I did not notice it.