Serial Port for Root Only

[Mike Dwiggins]

I have a USB serial adapter I am trying to use as a seial console device 
for putty.  It is identified and works like a champ for root but will 
not work for any other user.

For anyone other than root putty returns "Unable to Open Port".  I have 
checked proc/bus/usb/devices and can find nothing that would restrict use.

Is there somewhere else I should be looking?

Thanks