Try lookin through this webpage
http://forums.logitech.com/logitech/...thread.id=8882
I don't have a G9, i use a microsoft sidewinder. But i looked through the settings to see if I could find anything to help. If I go to start>control panel>mouse and then click on the "Activities" tab, there is a check box for "Click Lock" (This appears to be the same thing as what you're referring to as "drag lock")
I don't know how you went about searching, but you may have some luck using "click lock" instead of "drag lock" in your search term