Installing html2lout on Debian 5 (Lenny)

When I try to use html2lout on Debian 5 I get the following error message

Can't locate readonly.pm in @INC ... at /usr/local/lib/site_perl/Lout.pm 
line 192

Using cpan, I couldn't find a module called readonly.pm but did find one 
called Readonly.pm. I installed this and changed "use readonly" to "use 
Readonly" in Lout.pm but I now get this error message:

"$AT" is not exported by the Readonly module
  "Compilation failed in require at /usr/local/bin/html2lout line 11

Am I using the wrong "readonly.pm"? If so, where do I get the correct one?

Thanks in advance.

Paul Zarucki.