Other tasks works ?
Javascript problem. maybe a conflict with something else.
Did you tried on fresh install of Joomla ?
- Have a look in javascript console.
- Try to load your component with
index.php? .... &tmpl=component
(just an idea to see if when loaded alone it works)
EDIT : Front or back ?
Do you have other things on your page such as modules ? using javascript ?
I think it is due to a third extension on your page.
Does the problem occurs on every list views ?