Please describe the problem:
It is possible to press the Extract button multiple times for the same disc, with the result that it will rip the disc twice or three times! The only visual feedback you get is the little "number of tracks to be imported" goes up, which is easy to miss. Plus there's no way of stopping the multiple rips without cancelling the whole job.

Steps to reproduce:
1. Insert a CD with Rhythmbox open, and click it in the side pane.
2. Click the "Extract" button.
3. Click it again.


Actual results:
The number of tracks to be imported goes up. After importing the first time, Rhythmbox imports it again and overwrites the first copy.

Expected results:
I would expect the Extract button to be greyed-out if the disc was already in the process of ripping.

Does this happen every time?
Every time!

Other information:
Rhythmbox 0.11.6.