I'm using Arch Linux. Very often, when I click on something, the OS thing sees the mouse press but not the release. If it was a link or file I clicked, moving the cursor would drag it too. Hammering the same mouse button again gives no effect.
Usually, if I tap the touchpad (ALPS), the system finally sees both press and release of that, and I can continue working. (This might be because it uses a different driver - synaptics instead of evdev.)
As you can imagine, this is quite annoying even for someone who spends 70% of his life in front of a terminal app.
This is not a mouse issue - I'm on a laptop, and this affects both the Trackpoint thing and an external USB mouse.
This is not a DE or window manager issue - I have used GNOME (with Metacity, Compiz and Xfwm4), Xfce (with Metacity and Xfwm4), mwm, twm, awesome, and wmii.
Doesn't seem to be a hardware thing - after rebooting into Windows XP, everything works fine.
hal is used for the auto-configuration of devices (as I have to disconnect the USB mouse often), so Xorg.conf really has nothing of relevance.
Xorg -version shows:
X.Org X Server 1.6.3.901 (1.6.4 RC 1)
Release Date: 2009-8-25
X Protocol Version 11, Revision 0
If it changes anything, the laptop is stone-age Dell Latitude C840.
I kinda suspect either hal or the evdev thing to cause it, but I really have no ideas on what to check further.
In other words, HALP!#$ This thing is driving me nuts.