Ubuntu :: How To Reset Tilde Key

So I've made a bit of a mess of things. I installed Tilda and had it working like a charm.I bound it to the tilde key (shares a key with ~, maybe it's called grave?) and it was great.I also have a Logitech MX Revolution mouse and decided to use xbindkeys to fix the thumb wheel which is the only set of actions that doesn't work out of the box. I decided to set the wheel press action to the tilde key, hoping to have a button on my mouse to open Tilda.

After fumbling around trying to figure out how to identify the tilde key I somehow managed to bind it to xterm. This wouldn't do. So in an effort to clear the binding to default I bound it to "". Well now the key does nothing unless I use it in conjunction with the shift key, in which case it produces the normal ~.So here's my question: how do I restore that key to it's default function? I should point out that I just started using Ubuntu 10.04 exclusively a day ago and have had limited experience on Linux before this.