The use of sp_MSforeachdb can have unintended results. It will occasionally miss databases. There are better methods (such as a cursor - and considering msforeachdb is just a loop, a cursor is ok).

Here is an article talking about the behavior and a workaround.

http://sqlblog.com/blogs/aaron_bertrand/archive/2010/12/29/a-more-reliable-and-more-flexible-sp-msforeachdb.aspx

Here is a different version of msforeachdb by Gianluca that is what I prefer to use.

http://spaghettidba.com/2011/09/09/a-better-sp_msforeachdb/