I also just switched from 6.10 (1609) to the 6.9.5 (1639) and was wondering if 6.9.5 is really newer.
As a developer myself I guess that 1639 is the build number and thus is a few steps ahead of the 1609 beta although the version number suggest otherwise.
But Enpass 1639 now always tell me that there is a newer version and ask if I would like to download 1609. Can you tell us if the beta 6.10 (1609) is really older than the 6.9.5 (1639) and this is a 'bug' in the update routine suggesting an older version or if the beta is newer?