Does HTML::Parser pass its own testsuite on the troubled machine?
Why don't you post some code (with sample input) already?
Through testing I have come to the conclusion that
report_tags is not cumulative, and it works by reporting only those tags you ask for, ignoring all else,
and that ignore_tags has precedence over report_tags(that is if a tag is ignored, and you also want to report it, it won't be reported).
MJDsays "you can't just make shit up and expect the computer to know what you mean, retardo!"