Description of problem:
[UI] - [Networks] -  'Import' & 'Cancel' buttons are not responding and pressing on them will cause to unrelated parts of the UI to stop working. 

Once pressed on the 'Import' button under 'Networks' main tab, 'Cancel' button won't work(only 'x') and some parts in the UI will tend to stop working(basically the whole 'Networks' tab). 

Refreshing the web admin page will fix it. 

Version-Release number of selected component (if applicable):
3.6.3.3-0.1.el6

How reproducible:
100

Steps to Reproduce:
1. 'Networks' main tab > press the 'Import' button 
2. Try to press on the 'Cancel' button
3. Press the 'x' to exit the 'Import' dialog and try to add/edit/import network

Actual results:
Once pressed on the 'Import' button, parts on the UI stop working 

Expected results:
Should as expected.

Additional info:
Can't see any errors or exceptions in the engine.log, although it seems that an exception is thrown in the front end code once pressing the 'Import' button.

See also - BZ 1215727