Build identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; rv:1.9pre) Gecko/2008042606 Mnenhy/0.7.5.20005 SeaMonkey/2.0a1pre It seems, that the just checked in Tree-Twisties for Bug 430759 to implement the new Window-Icon-Set are a little confused. The new twisty-clsd.png now shows a box with a "-" in it, see: http://mxr.mozilla.org/mozilla/source/toolkit/themes/winstripe/global/tree/twisty-clsd.png This was the same, than the twisty-open.png before, don't think this was wanted. The new twisty-open.png now was a triangle pointing at right, which looks like the twisty-clsd.png from pinstripe: http://mxr.mozilla.org/mozilla/source/toolkit/themes/winstripe/global/tree/twisty-open.png I don't think, that this change of the Twisty-Icons was really intended.

See this on linux too (e.g. the thunderbird thread +- are now now >-)

This was due to multiple problems in the script that generates the winstripe icons for landing. The names on the files were inverted, and one of the aero files was missing a -aero which caused it to land in the luna theme. Files with corrected file names are attached.

The corrected icons were landed as part of a recent commit in bug 430759.

Verified=Fixed. Thanks for fixing this fast.