Can you suggest any setting in cperl-mode or a workaround in perl to make emacs highlight properly anything after case #2
I
checked out the latest emacs sources from Savannah recently (calls itself 21.3.50.3) and was delighted to note that the version of cperl-mode that was included (v. 5) fixed the formatting problems you describe. I had no problem using this cperl-mode with older versions of emacs; YMMV.
Previous versions of cperl-mode suffered from occasional hiccups, many of which may be worked-around by inserting a comment after the offending line.
MB