Apparently the definition of some columns in the sys.databases table is as follows:
If a database is not ONLINE or AUTO_CLOSE is set to ON, the values of some columns may be NULL. If a database is OFFLINE, the corresponding row is not visible to low-privileged users. To see the corresponding row if the database is OFFLINE, a user must have at least the ALTER ANY DATABASE server-level permission or the CREATE DATABASE permission in the master database.
and further down in BOL (SQL Server 2008 R2) it reads for the collation column:
Collation for the database. Acts as the default collation in the database.
NULL = Database is not online or AUTO_CLOSE is set to ON.
Hope this helps anybody encountering the same problem as I had today.
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