problem with map

[husher]

I'm working on the Forest map from the official website, wednesday night i did a few hours work clearing tree stumps from the field across the river from the farm shop, finished up and saved the game before quitting, it was a little reluctant to exit the map and go back to the main menu, other than that everything seemed fine. I logged on this morning to do some more work only to find that the game was seemingly stuck; it refuses to respond to keyboard inputs, i quit without saving and tried again later- same result the game refused to respond beyond the first tractor.
Does anybody have any idea whats wrong?
I'd prefer to salvage my progress but i'll dump and start again if i have to.
please bear in mind i'm no programmer so try to keep any advice simple.

Thanks.