Git push origin master returns Error cannot spawn ... why?

That reminds me of issue 313, where GIT_SSH environment variable contains spaces in its path.

Other than that, did you followed the GitHub Help page and checking if your ssh connection worked?

$ ssh [email protected]
The authenticity of host 'github.com (207.97.227.239)' can't be established.
RSA key fingerprint is 16:27:ac:a5:76:28:2d:36:63:1b:56:4d:eb:df:a6:48.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'github.com,207.97.227.239' (RSA) to the list of known hosts.
ERROR: Hi tekkub! You've successfully authenticated, but GitHub does not provide shell access
Connection to github.com closed.

I'm not sure if it was just stupid of myself, but I've solved the problem... Here's what I did (from advice, from work colleagues):

I was attempting to push changes in a local repo to an empty repo on github...

what i should have done was clone the empty repo, add the files locally to my cloned repo, added the files, commited the adds, and THEN push to the github repo...

$ git clone [email protected]:christopherdebeer/yUML-Diagram.git
 // added files
$ git add *
$ git commit -m "first commit locally"
$ git push origin master

My original problems might have been due to my totaly naivety as to gits usage...

I'm not sure if this is only a smartgit issue, but when this happens in that program its actually a permissions issue on the temp folder. It seems like windows 7 and 8 occasionally reset the permissions on the temp directory and you need to change them back to full read and write perms.