The box on the upper right corner that says “Piwik 0.2.37 is a collaborative project. If you like Piwik, you can help! Check out How to contribute to Piwik?” is interfering with that menu for changing sites.
Yeah, it was posted on trac.
But someone said that the same rule was in another CSS file.
So i commented out mine.
I refreshed my browser cache; the problem seemed gone.
But it has returned.
So, i looked closely in the other CSS file.
The rule there had height:auto as well as what i previously added to the first file.
Commenting height:auto out fixed the problem again.
So, i’m not sure of anything anymore.
Sorry.
For the record, all of this was with Firefox 3.0.10.