Just tried some more experimenting:
On playlists like these:
[Genre]=[Jazz],[Jazz//Crossover],[Latin Jazz] [Intensity]=<=1
[Genre]=[Rock],[Rock//Pop],[Rock//Surf] ~sort=[Random] [Duration]=>1:00
navigation does not get stuck, but the "searching" animation comes up for about a second after the first 17 down arrow keystrokes on the remote and then after every 10 keystrokes. I navigated through about 400 of 778 entries in the second playlist without getting stuck. If I reversed direction by using the up arrow the "searching" animation came up after about 5 keystrokes and then after every 10 up arrow presses. Cool, eh?
I wasn't able to find any pattern as to when it got stuck while navigating through my view schemes, but it seems to happen at the same place in a view scheme every time. I also noticed that after gettting stuck the first time, it would get stuck much more often, sometimes after each keystroke. At times it can't be un-stuck without hitting the "PC Link" button which I assume forces the player to search for a server again.
Finally I tried creating a simple view scheme containing only Track # under "View Items". While navigating through all track 1's (about 300 files) I found the behavior to be the same as for playlists. When I tried navigating through the "All" branch (about 3800 files) I saw the same pause after the 17th kesystroke, but this time the pause after every 10th became longer each time and got "permanently" stuck after the third set of 10 keystrokes. ("permanently" means the "PC Link" button needs to be used to get it un-stuck)
Hope this helps. I gotta go now, my thumb is getting sore....