Dear Paul,
I feel for you! I'm in the same position.
I'm just back from a 9.2 mile run which I managed in 1.37.05, it's slower than I'd like, but it was faster than the combined best times I've managed for the two runs I added together to get the total (3.2 and 6.0 miles).
The last six miles has some killer hills - 3 x 2 minute/steep climbs - and they just finish me. I find I have to stop and walk, then my legs tired, and it's a real psychological effort to get started again. Does anyone have a solution for this?! ;-)
I don't know about everyone else, but for me - this time around - it's the psychology I'm struggling with. I've done the FLM before (admittedly in 1998), and I know I was capable of doing the long runs then, but this time around it's been a real struggle.
Today I tried a lot of the psychology tips from the 'The Non-runner's Marathon Trainer' which has been helping me hugely (find out more here: http://www.amazon.co.uk/exec/obidos/ASIN/1570281823/falltpublishi-21