Can't type parentheses in Windows XP guest running on Ubuntu 9.04 host accessed over VNC.

[SirX]

I am running VirtualBox 3.0.4 on Ubuntu 9.04 with a Windows XP guest OS. If I make a VNC connection into my Ubuntu host, I cannot type parentheses (left or right) into the Windows guest OS. There is no response to the key press. No other keys are affected, as far as I can tell. I can type parentheses into the host over VNC, into the guest if I am sitting at the computer, or into the guest if I use RDP instead of VNC. This is sufficiently obscure that I have only found one other report of this problem: ​http://www.ale.org/pipermail/ale/2009-July/111969.html