I installed wxwidgets a while back, and now whenever I tell Synaptic
to Reload, I get the following error message:

W: GPG error: http://apt.wxwidgets.org gutsy-wx Release: The following
signatures couldn't be verified because the public key is not
available: NO_PUBKEY 0E0BCE7F53B087BC

When I originally installed wxwidgets, Synaptic warned that it could
not verify the key, but I told it to install anyway. I have since
uninstalled wxwidgets through Synaptic (but did not mark for complete
removal), but I still get the error message.

I don't believe I have gotten an update for Hardy since I installed
wxwidgets.

Do I need to re-install Hardy?