screenshot, annotate and zoom plugins interfere with mouse

Binary package hint: compiz

After enabling compiz via the "Desktop Effects" preferences item, the mouse becomes unusable:

* Left click does nothing
* Left click and drag creates a lasso which selects an area of the screen and takes a screenshot (the screenshot plugin)
* Right click and drag draws a red line on the screen (this is the annotate plugin)
* The scroll wheel zooms the screen, and often gets wedged

I was experiencing this on two completely different pieces of hardware both running 7.04; a Sony Vaio VGN-S260 laptop using built-in keyboard and trackpad, and a custom-built desktop using ordinary USB mouse and keyboard.

Disabling the screenshot, annotate, and zoom plugins appears to have eliminated the problem.

Other notes:

* Control+Left click appears to send a perfectly normal left click event
* Left click works as expected when clicking on small scaled windows in scale-mode (like Expose)
* Left click sometimes worked in menus, like the system menu

I had to use gconf-editor to disable the plugins, and it took a bit of massaging to get that change to stick. I'm not sure why, but often my changes in gconf would be discarded or overwritten. This may have been happening because desktop-effects was open, or it may be that some gconf changes don't take effect until compiz or gconf is restarted. Here is what I finally did that worked:

1. Start compiz via desktop-effects
2. Close the desktop-effects window
3. Start gconf-editor (use Control+Left click if you need to use the mouse)
4. At this point, compiz seemed to crash and I was back in metacity, I have no idea why
5. Disable the screenshot, annotate, and zoom plugins
6. Log out and log back in again (compiz started by default)

Other people are suffering from similar issues:

http://forum.compiz.org/viewtopic.php?p=10322

http://ubuntuforums.org/showthread.php?t=461896