This doesn't cover the cross-instance collation issues.

Using the default configuration for Linked-Servers will give you no end of headaches.

By default, the collation is eqated to the collation of the remote server/database.

TIP: If you have a linked server, make sure it's collation is set to the local instance/database.

that way you don't care what the remote collation is (even if it changes) as all 'data' will treated as though it were the local collation.