Need help with Zdaemon

So I have a Toshiba Satellite running Linux Ubuntu (I hate it and want to run Windows, but that's a different story) and use Zdaemon. Lately when I play, I can join a server, play with all keys (on keyboard), and look using the mouse. However, whenever I use the left or right mouse buttons, it exits the server. This is the second time I have had this happen (though I don't know how I fixed it last time). I have reset all options to default and even uninstalled Zdaemon, but it still does it. Any ideas???

Doom 4 already has a sourceport!?!?!?!??!

No idea why it does that, but in the mean time, as painful as this sounds try switching M1 and M2 to CTRL and ALT.
Also sorry to be the one to inform you, but wrong sub-forum for this. :/
Try posting in Doom General about this, or somewhere else.

Oops I forget I was still in DooM 4 forums. Sorry and thanks!