yeah, it is a lot of fun to have trouble with just one module for more than two weeks *g*
It's not a cygwin path and I am not using ppm with my cygwin perl. I've installed the ActiveState Perl to C:/usr/ to keep #!/usr/bin/perl as the shebang...
Yep - then it looks to me that all you have to do is use a Language-Prolog-Yaswi-0.08 that has been built using a version of perl between 5.8.0 and 5.8.6 (inclusive) .... or update to perl 5.8.7 (in which case Randy's ppm should work fine).
As regards the first of those 2 options, my offer still stands.