Success! Looks like we've fixed this one. According to our records the fix was applied for
a bug in our system
a recent build.
TreeGrid node icons
Another "not really a bug, but should be fixed, though" issue.
I set my node images like that:
Yes, those icons (+ and -) are added but they don't replace the default ones (gxt triangles are still there):
treegrid node icons.png