You'd be surprised at how the pros remedy problems with multi-paned windows. I had similar issues with a 14yo home we purchased. In my case, the glass was looking hazy and one even had mildew. Some of the processes the fixit-guys use are pretty amazing, like drilling tiny holes to get at and treat what's going on inside. I found this page, and it helped make my decision easier to hire someone --> Double pane window repair
It may help you, if you're still faced with the same problem. GL.