Had some trouble getting the ptkdb debugger to work, but I got it to work while I was waiting for my forum registration email to arrive.
I was getting an error message:

Can't call method "setup_main_window" ...

To install I had copied ptkdb.pm to the C:\perl\lib\devel folder.
To get it to work, I deleted ptkdb.pm from the devel folder and used active state perl package manager to install it. Here's what happened:

ppm> search ptkdb
Searching in Active Repositories
  1. Devel-ptkdb [1.1087] Perl debugger using a Tk GUI
  2. Devel-ptkdb [1.1084] Perl debugger using a Tk GUI
  3. Devel-ptkdb [1.1086] Perl debugger using a Tk GUI
  4. Devel-ptkdb [1.1087] Perl debugger using a Tk GUI
  5. Devel-ptkdb [1.1091] Perl debugger using a Tk GUI
ppm> install
Package 1:
==============
Install 'Devel-ptkdb' version 1.1087 in ActivePerl 5.8.7.813
==============
Downloaded 44300 bytes.
Extracting 5/5: blib/arch/auto/Devel/ptkdb/.exists
Installing C:\Perl\html\site\lib\Devel\ptkdb.html
Installing C:\Perl\site\lib\Devel\ptkdb.pm
Successfully installed Devel-ptkdb version 1.1087 in ActivePerl 5.8.7.813
ppm>

Now it works for me. Hope this helps someone else as well.