The white patches or blotches happen on some but not all logon backgrounds when they are stretched larger than their original size.
What usually works is to change one line at the top of the uifile...open it and look for this:
element [id=atom(contentcontainer0)]
{
background: rcbmp(100,6,#0,0,0,1,0);//rcbmp(100,6,#FF00FF,0,0,1,0);
and change it to this and save the file:
element [id=atom(contentcontainer0)]
{
background: rcbmp(100,6,#FF00FF,0,0,1,0);//rcbmp(100,6,#FF00FF,0,0,1,0);
Make sure you do this as the very last thing. If you open the logon in the Logon Studio editor it will change it back to the default and you will have to change it again.
