Try this then...  Copy your sof2mp.cfg file somewhere so you have a backup.  Then delete the original sof2mp.cfg file from the mp directory (or whereever it is).  Then run the game.  It should remake the config file for you with the defaults.  If this works, then you know that the problem is with your config file, if it doesnst work, then youve confounded me...    

yea me too.,

and the raven people cant help because they have other things to work on mainly Q4. so the last thing they are gonna worry about is the fact that you cant switch weapons. everyone here in the forums knows what they're talking about, well maybe with the except of uberfreak. but most of the  problems people have we can get fixed without the help of raven employee's. if the suggestions we gave you didnt work..,  well, we tried but someone like spike or ramrod may show up with something else for you to try but until then this is the best we can do fella.

btw what supersonic told you will probably work considering it remakes a new config file. also if you havent reset all your sontrols to default and then set em up again that might work as well.

Hmmm, I had the same. It was because of my mouse setup. I have a logitech mouse man and in control panel it was set to scroll 3 lines whenever I touched the wheel. When i played sof2, it would skip one weapon everytime I scrolled (check it out). When I put it on 1 line in control panel, it wouldn't help. However, when I put it on:

- autoscroll
- scroll 3 lines
- Use MS compatible scroll only
- Scroll in active window only UNCHECKED

it worked. If I changed ANY of these settings, I wouldn't be able to scroll normally, or use the middle mouse as secondary fire.
What I found interesting, is that when I checked: scroll in acvitve windows only, it would skip one weapon in sof2 whenever I scrolled! Dunno why, but hey, it works now.

Goodluck