2
The only place i now that this code i used in a clean install is.
/modules/system/templates/system_imagemanager.html
/modules/system/templates/system_imagemanager2.html
And it looks like this.
If $xsize and $ysize is not set, the code give error, and in sours it look's like this.
So the only thing i can think of is that you are using a bad module or side/center block, that have a template error.
Do you get this error if you have a clean install whit orginal themes, and no modules active.. ?
If not, you nead to look for errors one by one when you activate modules ,blocs and themes..