Interesting - I'm looking at the latest (28 Aug 09) Jep plates for VOR DME 04 L and VOR DME 04 R and I'm darned if I can see why you can circle east of 04 L and not 04 R. It's obvious why you can't circle to the west!
The only explanation I can think of is simply that the circling minima box for 04 R has been left blank - by mistake perhaps?