I have a similar problem. The artifacts are deployed using m2, the metadata on the repo is generated. When I do a build, maven logs that it has found a snapshot version and is checking for updates. It downloads and updates my local metadata for that repo, but DOES NOT download the updated JAR.
THIS IS A BLOCKING ISSUE. If a release is not planned soon, the fix needs to be back ported.
Having snapshots that don't update reduces the usefullness of SNAPSHOT to ZERO. Actually its worse than that, because we expect that SNAPSHOTS be updated from our internal repo and maven behaves as if it is updating them and then it does NOTHING. A fix in 2.1 does nothing for us if 2.1 doesn't get releases soon.