Just for perspective (and not solving your problem)...I've never been able to restart the debugger on Windoze. I've always had the same message. This was under several Perl versions from Activestate. Long ago I had the non-Activestate build, but I don't recall if it had the same problem, as I was new to Perl, and didn't use the debugger.

Perhaps someone else will be able to give a reason for this behavior, or even better, a fix.