ICollection interface no longer implemented?

I just updated from version 3.0.3.2 to 4.1.0.4 and now I have build errors in places where I was passing GoDocuments and GoSelections as an ICollection. Is this interface no longer implemented by these classes? Is this documented somewhere?

Is there an easy way to convert an ICollection to an IGoCollection (other than creating a GoCollection, iterating through the ICollection and adding each member to the GoCollection)?

This has a link to a document about the switch to generics: http://www.nwoods.com/forum/forum_posts.asp?TID=3027

Oh, and the release notes document has a list of links to previous release notes.