The subroutine "ParsCrossRefs" uses $* to get multi-line matching. This has been deprecated for ages and in no longer available in the current perl 5.10.
Without any understanding of the workings of "sub ParsCrossRefs" I took out "$*" and added the "m" parameter to all matches. It seems to work, I've attached the new info2html file.
/srv/www/cgi-bin/info2html