Here is their "What to do about ads" guide: www.sparkpeople.com/resource/motivation_ar
You need to follow that if and when ads are annoying you, rather than making message board posts. This will give them the information they need to be able to fix the problem.
FYI, I've been on Spark for five years and there are ALWAYS complaints about "ads getting in the way of my tracker". So no, they're probably never going to fix the root problem so it doesn't occur again. Just report it properly and let them know, when you see it, so they can fix that instance.