You didn't mention whether you're on the Mac or the PC, but I'll try to help. I'm on a Mac, running Live 6 with a PowerMate for zooming.
My setup is as follows:
Rotate Right is set to "Send Key". The key combination it sends is Shift + =, which zooms in.
Rotate Left is set to "Send Key". The key it sends is - (minus), which zooms out.
Click & Rotate Right is set to "Scroll Right".
Click & Rotate Left is set to "Scroll Left".
Click is set to "Send Key", and it sends the Spacebar (useful for starting/stopping Live's sequencer - could be deadly in live performance, tho!)
Hope this helps,
i forgot to specify.. i'm on a mac.. and this was a HUGE help. thanks