horizontal line when toolbar is collapsed

[Schlaefer]

I don't know if there are HIGs for this but I would say the conventional wisdom is to put an thin dark line between the collapsed toolbar and the window content. It looks a little bit awkward without:

http://img.skitch.com/20080420-c6sxup9kphuwxp4gscwba1r7m3.preview.jpg (http://skitch.com/schlaefer/jhbe/picture-1)
Click for full size (http://skitch.com/schlaefer/jhbe/picture-1) - Uploaded with plasq (http://plasq.com)'s Skitch (http://skitch.com)

[Mudi]

I also noted this visual problem a while back. Thanks for bringing this to my attention. Now I booked it as a bug and will be fixed...once :)