Entities Not Appearing in Settings After Import

In CRM 4.0 and now 2011 I've had an issue when I import customisations/solutions which have entities that are setup to appear in the Settings area. The problem is they just don't appear!

This has been one of those niggles that I've always been aware of but never done anything about, put simply it's always been quicker to just tick the settings box, save, and publish. Well this morning something has changed and I did a bit of digging.

Apparently you need to include the SiteMap in your export, even if it's not been changed, and hey presto the entities appear in settings as they should.