Geospatial index cannot be used in $and criteria of a query?

Question posted on mongodb-user here http://groups.google.com/group/mongodb-user/browse_thread/thread/41173a4a2c62f0be

Quick synopsis is I'm getting this error back from the shell

Wed Dec 28 12:39:01 uncaught exception: error {
"$err" : "can't find special index: 2d for: { $and:[ { geometry.centroid:

},

] }",
"code" : 13038

when using $near on a geospatial index in an $and query. Pulling the $near outside the $and gets the expected behavior.

I can't see any caveats in the docs on geospatial queries or $and that indicates any restrictions here.