Sometimes, when running Debian Squeeze 6.0.4 under VMWare Player, the left mouse click gets stuck.

I cound not find any good fix for this, and until I get a better solution, I remove the psmouse module kernel and I add it back, like this:
$ sudo modprobe -r psmouse
$ sudo modprobe psmouse
Also, for an easier use I have created this alias:
alias fixmouse='modprobe -r psmouse && sleep 1 && modprobe psmouse'
Now, all you have to get your left click back is to type sudo fixmouse, in your terminal.
To make this alias persistent, do this:
$ echo 'alias fixmouse=\'modprobe -r psmouse && sleep 1 && modprobe psmouse\'' >> ~/.bashrc