I've upgraded to the latest from ActiveState, 5.8.1 build 807, and that still gives the same response you got "Recompile Perl with -DDEBUGGING to use -D switch".

There are instructions in the ActiveState installation notes on how to upgrade, though upgrading from 5.6.x to 5.8.x most likely means you will first want to de-install the old AS perl and then install the new.

Whether you will be able to recompile from source depends on whether your system has a compiler on it.   I've not bothered with an MS compiler for some years now, prefering to make do with AS's offerings.   Another option is installing and building under Cygwin and the like environments which do come with compilers. I've got Cygwin, but again, just haven't needed to rebuild.

I'd say, unless you have a crying need for a built-from-source Perl feature, such as -D debugging features, don't bother with all that bother.

Of course, people could volunteer compelling examples of what I've been missing by not building my own ...