In reply to andy_1972:
I've only done a handful of 7a's at the wall, but perhaps that means I've recently been going through the same thing? Anyway, the following thoughts occur. [A lot of this may be old hat to you, in which case apologies! but you didn't give us much to work with
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(1) do you boulder V3 solidly? i.e. you can do all the problems at the wall in 1-3 goes. If not then your power or technique may well be holding you back. And if you don't boulder, then you should! Identifying what sort of V3s you can't do will go a long way towards identifying what technique aspects or physical weaknesses you should address.
(2) how many leader falls have you taken in the last 3 months? to get up 7a climbing efficiently, you need to take risks, by which I mean you need to pop/grab for holds/moves you may or may not hold; if you don't accept the risk of a leader fall you will do all sorts of other things and establish bad habits. Very hard to be honest with ones self about this one, but the answer to the question I posed is actually very simple; if the answer is less than 5 falls then read about clip-drop training or buy 9/10 climbers (or Rock Warriors Way) and get on with it. I found this very VERY hard to face up to, and it made a big difference when I did, even though I haven't got it fully nailed by any means.
(3) can you do all the moves on a 7a but only in 3-4 sections? in this case tactics or stamina may come into it. This is the least likely IMHO, but lapping the same 6b - 6c four times with 30 - 90s rest has helped me in this area. This is not just a fitness exercise, it trains you to climb efficiently, to rest, and to hang on psychologically when you're pumped.
(4) if you think your fingers are just too weak, try fingerboarding once or twice a week. If you don't already do some then the gains will be pretty fast for this investment of 1hr/week - you'll notice the difference within 6 weeks if you do it right.
Good luck!