Disappearing Themes

HI,

I’m getting some very strange theme behaviour in a local install of wordpress.

There are three themes installed, twenty twelve, twenty thirteen and twenty eleven.

However, only one at a time will show up in the manage themes admin panel. On the install themes panel all of them show as ‘installed’. If i remove one and re-install it then activate it straight after the install process then it gets activated but the previously activated theme disappears.

I have removed the entire installation and database and re-installed wordpress but get the same errors. Any idea what could be causing this?