It appears that Perl 5.8 no longer installs a /usr/bin/perl5 executable, so running /usr/bin/perl5 is actually still running the old Perl. It sounds like the ISP made a mistake - when removing the old version of Perl, they ought to have either removed this file, or symlinked it to perl5.8.2.
For future versions, I've changed the path-to-perl detection code to look for /usr/bin/perl before /usr/bin/perl5. A couple years, looking for /usr/bin/perl5 was the better option as there were still a few servers out there with /usr/bin/perl being a Perl 4 executable, but hopefully those are rare - any users on such a server will now have to manually change the path to perl, but people installing on new servers won't run into this problem. It won't automatically fix upgrades, although you _could_ change the path to Perl in the config file, and then "upgrade" (even to the same version) your product to have all the paths upgraded for you.
Jason Rhinelander
Gossamer Threads
jason@gossamer-threads.com