We have AdWords on our site. We've recently moved to a new host and they work sporadically.

When visitors use the default url to our site, without index.php on the end, there are no ads, if they use the url plus index.php, the ads show up.

When a client is logged in to our site, the ads appear. When they click on our home link, they disappear.

What the heck is going on here that could be causing this and how do I figure this out? I am just stupidly confused about this and how it works.