update from Joomla update screen

I just installed the newly released MJ 1.0 (had to install from directory) and there is an update for it in the Joomla extension manager update screen. When I click on update the page sits trying to reload for several minutes. I have to refresh the page and it says it installed successfully but the update is still there.

I'm on Joomla 2.5.1

Any reason why this update is here and why it does not work?

It's fixed in MJ1.0.1.