Steps:
1. Create a Qt Quick Application.
2. Choose symbian device platforms, others are default until finished.
3. Run the project.
4. Press the Cross button to closed tab.
5. 'Untitled on Symbian Device is still running on the device...... Would you still like to terminate it?'
6. Press 'Force Quit' button.

Actual result:
Error note pops up, qtcreator.exe needs to close.
(Please see the attachment file.)

Expect result:
No error shows.

Comment:
Tested with E6 device and Symbian Anna release.

SDK package is 2011_10_18_10_55_NokiaQtSDK.exe

Qt Creator 2.3.1
Based on Qt 4.7.4
Built on Sep 21 2011 at 10:51:01