And if your story line varies from your original outline...change the freaking outline. I've always felt that rigid outlines stiffle the creative novelist. I don't use them. If you really know your characters, they will tell you their story. Just write.
I don't have an outline. Maybe that's the problem. I keep it in my head.
The best way to get around a block, in my opinion, is to open up a new character with a completely differant perspective.