I know how completely annoying the Logitech drivers have to be for some when they use fast user switching. So here's my solution to the problem:
First make sure you are using WinSwitch to change users, as we need its functionality. Next, you'll need this AppleScript:
on pscheck()
tell application "System Events"
return (get name of every process)
end tell
end pscheck
tell application "Finder"
set e to my pscheck()
if e contains "LCCDaemon" then
tell application "LCCDaemon"
quit
end tell
else
tell application "LCCDaemon"
activate
end tell
end if
end tell
Now save the AppleScript as an application, and drop it in both your ~/Library -> Application Support -> WinSwitch -> Switch-In Items and your ~/Library -> Application Support -> WinSwitch -> Switch-Out Items folders. Something named LCC Spawn should help you remember what this app does. Make sure you also copy this script to the same locations for each user you plan on letting use the Logitech drivers.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20041104142244497