When I'm debugging something like this (just did a biggy) I print "Content-type; text/html\n\n"; at the top of the program even before "use" statements. Then you can see what is getting printed.

One problem you may see if you follow this track long enough is that cookies and redirecting don't like each other. Another headers problem. My solutions were,
1) keep track of how many times you print $q->header
2) to keep sane, slurp in a file and print it out instead of redirecting to it, if you are going insane
3) do cookies in Javascript.. and write variables into the javascript at runtime by using a template which you've actually slurped in with (2) above.
4) if you must do cookies in perl, get all your functions that do cookies and put them all together into a couple of functions like doallmycookies(). Or better yet stick everything inside one cookie. I got away with a heavily javascripting page that opens up first and finds out who's knocking on the door, but that's only because a client asked for lots of functions that wanted to use cookies at the end of the project..

I believe you can even roll your own comlicated headers in text but I prefer CGI to keep sane.. maybe you want to read the RFC if you get really into it.

P.S. If anyone knows about a non-mod_perl way to do clickpath tracking, so that the cookie gets into the apache log file, I'm interested! (no to webbugs..) I've done mod_perl but this is for a server where it isn't so easy to turn it on and off and shake it around in the air.

Hope this helps.