This is a known issue with Samsung TVs. It happens because the version of Netflix you are using is not compatible with the version of Smart HUB (netflix was not intended to run on local versions of the smart hub software).
The only thing that appears to have worked for some of our customers is:
- Set the smart hub country to a country that does not have Netflix e.g. Singapore (to remove the app)
- Then set it to the UK or Australia (to install an older version of the Netflix app)
- Then configure Smart Hub not to auto update apps (as per http://www.samsung.com/us/support/howtoguide/N0000058/14611/185292/UN32F5500AFXZA)
If this doesn't work, there is not much that we can do about it unfortunately as it's a software problem on the TV itself. Hopefully Samsung will fix the issue in a future software release.