Ive just upgraded to 4.2 RC2 and after rebuild found that all links to assets, linked to posts, have gone away. Managing the asset I see that it is linked to post, so it seems that template tags like mt:EntryAssets havent been parsed.
Any suggestions how to fix it?

I believe the bug has been fixed in this changeset, which is unfortunately not in RC2.
http://code.sixapart.com/trac/movabletype/changeset/2563