I am new to this game.  I loaded software and used successfully for days.  During one game, I was suddenly unable to change weapons using the mouse wheel.  I tried everything including changing options to move to next and previous weapons (I switched to the up and down arrows and other keys), rebooting computer, and reloading software (twice).  Nothing has worked.  Everything else in the game works great but I cannot change weapons more than once after I start a new game.  I am really getting frustrated.  Help!

Hmm I had the same problem in Q3A...the mousewheel worked fine,then after I changed my Controls in the Control-Options..
poof mousewheel dead....
Hmmm that problem never showed up in SoF2 tho...
If it happens again (after you changed controls...I don't know if it happens when you changed them) just leave the controls like they are.

Another reason might be the safeness of weapons...afaik will only safe weapons be selected with mousewheel
But I am not sure if thats the source of your problem...

u can set up in the options that any weapon will come up wiuth the mouse wheel rather than just safe ones

i had the same thing happen after a few days of using the mouse wheel without any problems.
but then it seemed to right itself after i dropped a weapon and then picked it up again.
try pressing 'T' and then running over the weapon.
who knows, it might work.