Ah, thanks for clarifying things. Now I have the code licensed under an MIT license. Out of curiosity, what are the implications of changing the license on software you've already released?
As far as I know, there is no problem at all issuing code under a new license provided that everything in the code is yours. The only tricky issue I can think of is that you can't really revoke an earlier license, so if you are moving to a less permissive license you can't stop people from redistributing under the previous license. So if you decided to relicense from something like BSD to GPL, you couldn't stop people from releasing the earlier version under the BSD, but there is nothing keeping you from only hosting and working on the GPL branch.