I came across weird issue, I created a task list with the system account.
This list is not able to view by any other users.
Spent enough time on finding a cause. It was all due to IE, it was working fine with Chrome and other browsers.
To make it work with IE:
1. Active x and JS permissions has to be enabled.
2. The site has to be in the trusted pool of you internet explorer.
3. Disable any extra add-ons.
Hope this small piece of information will save time