I'm using Jbed 20080912.5.1 as well.
Was just thinking of trying Jbed 20090506.2.1, which is the newest I could find, but I guess, why bother, if the one I have works fine.
Also, I finally found the right thread for making Mini 5 the default!
http://forum.xda-developers.com/showthread.php?t=382043
He needs to update it for Beta 2 yet, but it looks like it's supposed to work.