I can't believe i'm writing this, but here goes:

In all SmartGWT styling the various classes representing over, selected, down etc. begin with Captitals ,e.g. "Selected", "Dark", "Over".

However, the default "selectedIconSuffix" in the TreeGrid class is "selected" !!!

This clearly an abomination that goes against all known laws of nature. Surely we cannot rest until this has been remedied.

(On a serious note, it stumped me today...)