When life gets you down you have to learn to pick up the pieces.
When your plot is falling apart you have to know when to pick up the pieces.
When your characters are fighting you have to know when to pick up the pieces.
I think you can see the theme. Learning when it's time to move on and allow yourself to either trash it all and begin again or work with what you got.
It always takes me longer to realize that my characters aren't working than it should. I guess I want them to fit so badly that I'll do anything to get there, even if that means putting them in a bikini in a snow storm because they like the sun (yes I want them to use their imagination).
For those who can't pick up the pieces themselves (I'm one that experiences this quite often), friends are awesome. That's right... blog friends. They are always there to remind you that you don't suck. You're just having a sucky day.
So when do you feel it's time to pick up the pieces?