Hmmm.... the grep on 5.8.9 shows that PL_curpad is #defineed. If you get the error "symbol missing" for this name, this means that one of the generated files does not see the header file where this symbol is defined. Further, it means that a K&R (i.e. non-ANSI) C compiler has been used, otherwise this would have failed already when making Perl.

Just a wild guess: Since the differences between 5.8.8 and 5.8.9 are huge WRT PL_curpad, could it be that Perl on your Ubuntu machine somehow (maybe via PERL5LIB) finds a version of that module which had been compiled for a different platform? Did you try to recreate Perl from scratch, from the sources?