D'oh! Changed my mouse settings, now I can't change angle w/wheel button!

I'm sure this has happened to someone else out there...

I have a logitech 2-button optical mouse, with a middle scroll wheel. I installed the Lotitech control center (sic) and in preferences changed a few things around, of COURSE not making notes on how it was setup at the time. Now when I click the middle button (scroll wheel button), it no longer works to change the viewing angle of the game.

I know I can press the Tab key and do it that way, but as I'm not used to doing that I don't have as much control as I did doing it 'the old way.' Does anyone out there have the same sort of mouse and can tell me which of the many settings to set the scroll wheel button to to get it back to where it was?

Tried ditching the Logitech preference panel to see if it would revert on its own - no dice.

Not a huge deal, but it's costing me personal comfort points...

Thanks!