Rated 3 out of 5 stars

First of all: Great work!

But I've a problem with the expand/collapse icon from folders (e.g. in the left pane). I analyzed that problem a little bit and found out that the icons in 'global/skin/tree/' are not displayed. These Icons are replaced from thunderbird with a default icon (which always seems to be collapsed). I don't know why thunderbird does this, but it is pretty annoying.

I am running thunderbird under kubuntu 10.10 (maverick). Maybe this problem only occurs on linux-distros...

It would be so nice, if you could fix this little (but annoying) bug!