Comment 3 for bug 507247

Actually, the rules file is quite old. I'm not sure why it's only just showeed up in this form, but I think some changes to usbserial have affected the ability to have more than one application using the device. This may have been there previously (or perhaps from the point where devicekit took over from HAL) but it has only recently generated the 'device busy' error.

I think modem-manager generated a similar fault but has now been fixed.

I'd be interested in knowing what the changes were in usbserial or ftdi drivers, and what they were intended to do - I think another problem with blocking reads has recently been fixed.