This is a common issue in Bigfoots from about 2003-04-05. The inner seal creeps between the double panes. The function of the window is not affected, but the look is pretty bad. I have one like this on my 04. The window cannot be repaired, but needs replacement if you can't live with the look. These windows
are made by Sunview Industries in Summerland, BC, Canada. Their phone number is 250-494-1327. The rep I last talked to is Kent. Kent says that the problem is now resolved in windows
made in 2006 and after. Sunview will sell you a new window, but they are not offering any warranty deals for this issue.