Although I have no trouble with any of the reels (except Devils Dream which I don't know) listed there are some tunes that have defeated me on the tenor banjo because of technical difficulty but these have normaly involved a passage moving up the neck a little - beyond the B on the first string. One I can play if I paractise at it but always find difficult is the Moving Cloud.

Often if I find a particular passage is bugging me in a tune that I am learning, I will modify or simplify it slightly to suit my playing.

Also, as mcmoo mentioned, I think that it is possible to have a mental block with a tune. The Monaghan Jig is one like that for me. There is nothing difficult about the tune but where it goes and where my brain tells me the melody should be going are different and in 12 years, I don't think I got through it once without getting lost at some point.

Another varient on the mental block theme with me is the tune that changes half way through, e.g. The Tailors Twist has an infuraiting habit of ending up as the Manchester Hornpipe.

I noticed a couple of people mention cramp or other aches and pains. If I dive in with a couple of fast reels, I can end up with tightening across the back of my right hand and a cramp in my left forearm. The solution for me is simple, warm up first - I like to start with a couple of gentle hornpipes. Having said that, I would guess that the problems mentioned here are caused by the sheer difficulty of the tunes.

Jon