greatbeast Argh, that's SO frustrating!! It sounds like both you and @DiAgi are experiencing similar issues, so I wonder if other users are having trouble too, or if it's maybe a location-based problem. Since you mention that it's only begun happening since the Xmas offer ad started, maybe @Admin could disable the ad temporarily, then post here to say it will be disabled for a certain length of time, then you could go in and see if the problem is directly related to the Xmas ad. I don't know if this is do-able or not.
Whatever happens, I hope it can be figured out and fixed for you soon!