Macs does nativly support mice with even more than 5 buttons. Its just lack of configuration options that buggs me
Yeah that's what I meant in terms of being "supported". I don't like it how you can only configure/customize an Apple mouse unless your third party mouse has it's own software. I hate installing their crap. So, the Service Rep was technically right, but it only affects Apple mice, and nothing else.
Any-who, you said you tried USB Overdrive. How long did you wait? I've had take a minute or two (it seemed) in recognizing a device. Sometimes having to unplug it and try again after the system had booted.
There is also the GamePad Companion app. Similar to Overdrive, but for one reason or another it might recognize your mouse when Overdrive can not.