Regarding workrooms in EPiServer 4.61: if you try to delete a workroom list page that has one or more workroom pages as children from the Recycle bin, you get the following error message:
DELETE statement conflicted with COLUMN SAME TABLE REFERENCE constraint 'FK_tblPage_tblPage'. The conflict occurred in database 'dbXXX', table 'tblPage', column 'fkParentID'.
You can get around the problem by first deleting the individual workrooms from the Recycle bin, and then the workroom list page.