Keydown/Keyhit don't detect Print Screen!

Running this code:

While Not KeyHit(1)
  For f=1 To 255
      If KeyHit(f) Then Print "you pressed key: " + f
  Next
Wend

Every key I hit on the keyboard display a scancode... except for Prt Sc/SysRq!

Tested both on XP Home and 98, neither prints anything when I hit Print Screen.