iMovie 10.0.06 won't share to Youtube

I'm using iMovie 10.0.06 and it won't share to Youtube.

It did do this once before on a test video but now I can't share my movie to Youtube.

"Invalid account name or password"

As far as I'm aware this has not changed. I assume this is the username and password for Youtube channel (which is same as Google+ right?)

Does anyone know if I go the manual route of exporting to file and uploading to Youtube whether I will lose quality?

iMovie 11 exporting to Youtube used to compress the file horribly.

Any ideas?