When you say
"I can get the picture on the tv to stay on if I change from sat to tv very quickly when it looses the picture"
Are you saying that the action of switching from one source to another makes the TV work, no matter what source you are switching too ?
Please recap on exactly what happens when the picture goes and comes back, for example when the picture goes, does it fade away or go immediately ? when the picture comes back, does it appear as a immediate clean picture ?