If choosing one of my layout themes - for some strange reason I noticed site graphics get stuck on one so - just a note
many of my center backgrounds are transparent which is written into the code
Please make sure that the site images or other standard Ning layout images are removed before placing my code in your advanced editor
the Standard site images can usually be found in your My Page Appearance section under the All Options tab - the top section is named color - Please set all the image boxes there to "NONE" if they are not already set to that and click save - then you should not have any interference with my layouts.
If this is a continued problem - in the future I can force a transparent or appropriate background tile in the middle of the layouts but for now I did not use one where it is not needed.