Maya default settings
 

Hi,
I change attribute values in the Channel Box using the MMB and dragging from side to side. Each time I start Maya the value for the speed of the change is set to Medium. I can change this to Slow on a per session basis using the Channels>Settings menu option but each time I restart Maya it reverts back to Medium. I have tried to find the option to make the change across sessions under Window>Settings/Preferences>Preferences but cannot find it. Can someone tell me how to make this change?

Thanks,
Ron