wow really? macs don't have a delete key? no wonder no one uses them... lol j/k
Sounds like a bug then, you will have to wait till one of devs respond.
It's not enough, because there are not manydevs thare are also mac users.
I would like to have one (at least for C::B development), but no one pays me to buy it :cry: .
To (hopefully) fix your issue (or at least work around it):
try to disable the keybinder-plugin: Open "Plugins -> Manage plugins...", scroll to "Keyboard shortcuts" and click "Disable".
If I remember right there was exactly this error (behaviour like a stuck Cmd-key), that should be fixed in the pc1 version, but there seem to be still issues with it.