DataMapper stumping me - almost works

[eluser]BrianDHall[/eluser]
On further testing I find the same problem, but what I did find was that when I update a listing it correctly updates the relationship in the join table.

In the manual it seems to use just exactly this technique and it 'just works', but here it just...well, isn't

Is there some other way to load relationship info? Perhaps another method to make the listing contain the member values of the garage type, so I can just pull a listing and access the display name of it's associated garage type?