hmm, you say you are doing an init... I'm a bit confused why its doing a push then.
id have thought, it will only do a push, if the repo is dirty ... i.e. changed files.
ok, i need you to do the following...
preferences -> reset all
edit contrib, enter your details
do init ( it will say its going to delete dir, say yes)
then after its complete, i need you to copy the entire console log to a file, then upload to dropbox (or similar 'reputable' service) and post a link here to the file.
perhaps something else is going wrong....
it looks like credentials issues to me, which would give you this error, but from what your saying, its not... and we have not had any other reported issues with this, so I'm basically at a bit of a loss.
btw... can you confirm what OS versions your using, and i assume your using 1.0.12 without any other issues?