You have am unintentional closure, created by using subroutines that refer to lexicals declared outside their scope. This is a known problem with Apache::Registry (but not with standard mod_perl handlers written to the mod_perl API). You can fix it by moving the CGI parameter code inside the init sub.

For more on this topic, see the guide. Also, turn on warnings use full strict (not just vars) to catch this sort of problem.