been chatting it over with a mate at work today and he said similar to TW above.
My bowling has improved massively this year compared to the last few (in that I used to just hope it didn't hit the side netting, now I hope to be making the batter work & threatening teh stumps).
It might be that I've reached a speed plateau where I'm trying to improve the speed of my bowling, but not adjusting release point etc, so I just need to keep working through it.
Buzz - I've tried focussing on where I want the ball to land, top of off etc, but find my most comfortable place is to look at the base of the stumps (it was what worked for me in terms of accuracy of line and pitching it up), maybe I should try looking at the top of the stumps again to see if it tweaks my release point.
Re the run up length - I've just found a length that I can run in off without having to stutter/skip to make sure I was landing in teh right place. not sure I want to mess with that too much as I actually feel quite nice through my action (just short...)
Also, if I shorten my run up to work on my action, I feel there is a chance that I won't be able to repeat the action and speed it back up if I re-lengthen my run in. I'm certianly quicker off my 'normal' run up as I feel my speed and shoulder are matched, where as a shorter run up I try to put too much shoulder into it.