I agree, more info. "White stuff" brings different images to different people. For example, is it a white foam, is it solid looking, soapy? And the more info you give the better chances that you will be answered accurately. To me, it sounds like water build up by the way you described it being white and stuck to the side of the glass. I'm definately out of my league when it comes to diseases.
Hope you find the answers you're looking for.