The button dose not look in correct status when pushed by keyborad

S10 U2 b03, mustang b73, both x86 and sparc.

Reproduce steps:

1.Launch mozilla
2.Load SunTea
3.Input something in the textfields
4.Move focus to the Clear button by Tab key
5.press space key to push the Clear button
6.Move focus out of the button the button looks still in pushed status
7.Move focus back to this button, press space key, this button works but still looks in pushed status