The ORMapper has been updated again today.

 The following important new feature is why this is a major update:
 
 * Added IsolatedContext Property to Create New Isolated ObjectSpace
 * Use IsolatedContext to Isolate all Tracking/Caching to that Instance
 
 Then there are these important bug-fixes as well that were rolled in:
 
 * Fixed Delete with Lazy-Loaded Many-To-Many removing Related Objects
 * Fixed StartTracking clearing any pre-existing Relations on Objects

Whenever Paul Wilson comes out with a new release, he updates releated questions/issues in the ORMapper Forum.  This can give you a better idea of how those changes apply or may benefit your own project.