Upgraded an existing 1.5 site to 1.7 on the weekend and all went well and loving the speed improvements.
Had a strange issue today where all blog content dissappeared from view, on investigation I discovered that the entry in Orchard_Framework_ContentItemVersionRecord for the Blog had had it's ContentItemRecord_id set to null.
Which was fixed with the below update statement.
SET ContentItemRecord_id = 98 WHERE Id = xxx
The only action that had occurred on the site since finishing the upgrade was correcting a blog posts title, and unapproving a large quantity of spam.
I can't pin point at which point the blog entries dissappeared from view but am wondering if anyone else has experienced this.