I've done a lot of work on B::Deparse since perl 5.6 came out, and the development snapshots of perl have a lot of fixes which aren't in the version that comes with 5.6.

Unfortunately, B::Deparse is very intimate with the internals of the interpreter, and so you can't upgrade it on its own. But if you're feeling experimental, try downloading the latest development snapshot of perl from here. Go for the one with the biggest number - it indicates the patchlevel. (The latest development snapshot is also called bleadperl, because it's on the leading/bleeding edge.)

And yes, I did fix the /x bug. Your example works fine with bleadperl. Of course these fixes will all be in perl 5.8 when it's released.