Abrowser: Enable/Disable buttons in Add-ons Manager don't reflect actual change of state when pressed

Package: abrowser
Version: 7.0.1+build1+nobinonly-0ubuntu0.11.04.1+5.0trisquel2

Steps to reproduce:
1. Abrowser / Add-ons (opens "Add-ons Manager" tab).
2. Choose "Extensions" subtab (you could try the same with "Plugins" as well).
3. Find, for example, "FlashVideoReplacer" row. There should be "Disable" button for it (if you haven't disabled it).
4. Press the "Disable" button. Note that text for the button haven't changed. It is still shows as "Disable". Nothing is visually changed at all. (Expected behaviour: the button text should change to "Enable".)

Workaround:
5. Choose other subtab ("Appearance", for example).
6. Choose "Extensions" subtab. (Now the button displays as "Enable".)