Bug in Segmentation Editor with IE7/8

Hi there,

as I had no luck in the German forum I'll try it here.
We did the update from 1.7 to 1.12 and now we have found a small problem within the gui.
With IE 7/8 the dashboard cannot be rendered. Starting from the segment editor nothing is shown and we get the following JS error:

'definition' is Null or not an object (within the comprimized JS at line 1427 where the segment <li> elements are generated; access via segment.definition)

With Firefox there are no problems and it works. If I deactivate the segment editor it works with IE again.

Is it a known issue? I haven't found anything.

Regards,
Thomas