Home screen Background problem on Symbian Belle

[EmreA]

I am testing a theme on RDA. Everything works well but background doesn't change. Before installing theme, If there is any additional background on home screen, installed theme does not change it and previous background on the home screen still same. I changed "Active background" and "Home screen background" in Cardibe.UI Symbian, but it doesn't work when i test on RDA.
Can you please help me what i do wrong?

[EmreA]

Additional information:
Test results on Nokia C6-01, Nokia X7-00, Nokia N8-00 :
There was additional background before installing theme, and installed theme did not change home screen background.

Test result on Nokia C7-00:
There was no background before installing theme. Installed theme changed the background without any problem.

[flotron]

Did you disable the original wallpaper from factory belle? The screen must be black before you apply the theme

[EmreA]

i didn't disable. Thank you for help!