I have had things running just dandy on my MS IntelliMouse Explorer for a million years, until I recently ran an apt-get upgrade. In fact, everything was fine after that until I rebooted...

Now, my mouse wheel and its extra buttons aren't functional anymore. The <b>zinger!</b> is that all my previous config is still intact. My xorg.conf still has the same lines for the mouse that it used to, imwheel is still supposed to be running at X startup, but I can't seem to find it with a `# ps aux | grep imwheel`.

Not sure what messed with my mouse!

Perhaps the package got updated and installed the default config file without you noticing if so then the imwheel will not be getting loaded as it defaults to off.

Edit: I have a post here on getting my MS Optical Trackball working you may want to check you have all the files necessary if the package changed to a newer format as well.

Nope, I checked that imwheel is running when I start X; the config files are all still there, all still intact just the way I left them.

I have a clue, I suppose: part of the scheme was the order of the buttons on the mouse had to be remapped, which was accomplished with the fairly well-known command:
xmodmap -e "pointer = 1 2 3 6 7 4 5"

However, when this command is run, xmodmap takes a nose-dive! This is what I am given instead of a working mouse:
$ xmodmap -e "pointer = 1 2 3 6 7 4 5"
xmodmap: commandline:1: bad number of buttons, must have 11 instead of 7
xmodmap: 1 error encountered, aborting.

This always worked before, I have no idea why xmodmap thinks I have four extra buttons on my mouse all of a sudden. As I stated in my earlier post: all my other config files are the same. xorg.conf explicitly states I have seven buttons, -not- eleven. Anybody fluent in xmodmap-ese?


==EDIT!==

Apparently it must have been an upgraded xmodmap that's at least partially to blame. I have come to discover that my imwheel arguments:
imwheel -k -p -b "6 7"
No longer likes having spaces in it, so I believe I need to use:
imwheel -k -p -b "67" instead. I am not really sure, but with the space, imwheel gives me an error, and without it, everything seems to run smoothly.

The big change however, must be xmodmap: I am thinking it "detects" more buttons to be more compatible with all these newfangled mice covered in zillions of clicks, axes, and doodads...
For me, this used to Just Work:
xmodmap -e "pointer = 1 2 3 6 7 4 5"
But as HappyTux pointed me to, and as many other Debian users have been coming to learn recently (some of us quite recent! ...as we don't have to reboot or restart X very often!), I discovered to get the same functionality, all other things staying the same, I now have to do:
xmodmap -e "pointer = 1 2 3 8 9 4 5 6 7 10 11"
I have no solid idea why, but hopefully this will point someone in the right direction. I was baffled, because I still don't have eleven friggin' buttons, but oh well...

Nor do I have 13 buttons with an X config saying 9 .... Oh well that is the way it goes sometimes good to hear you got it going BTW.