I have the same problem. Everything was working fine, then last week when I pressed the home button kept getting asked the touchwiz question. Very annoying. To make it worse I cleared the data for Touchwiz and lost all my setup, now have to do it all again!
I have still got the problem above even though I have to set my phone up again. Pressing "always" should do it, but it only lets you use the home button for a while, then it kicks in again. If you press once, then next time you press the home button it kicks in straight away. I need to find out what is making it kick-in after pressing always. You get to use the phone for a while and then suddenly it asks the touchwiz question.
If I can make it happen then I can show someone at Samsung the problem, but now if I go to them the problem cannot be shown as it is happening outside of my control.
All help here appreciated