I think the "arrow" navigation is very confusing for users. They are used for two different purposes in two different places: when you are in a forum, they are used for prev page, forum index, next page. when you are in a message, the are used for prev thread, forum list, next thread. This is the same even if you are in threaded, collapsed view (where personally, i think they should go to next message).
I mentioned this before (sorry to repeat, but I'm just trying to get my thoughts together) but I really like the 'threaded' concept for the forum lists that UBB uses. This makes it clear that you are in a forum lists, and how to get 'up' and where up takes you. This also works very well for the message level. When you are in a message, there is a folder subdirectory view that allows you to go to the forum list and to the forum index and it is indicated that one is 'above' the other. Currently, when you are in the forum list, both the arrow and the "Forum Index" lead to the same place. Quite confusing and quite inconsitent.
I would love some easy alternatives for this navigation area...
-EB