While looking at the corrector on the 14 off-axis last year, I noticed a few, small, shiny spots. I found out that these are caused by pollen. It settles on the corrector and burrows into the coating, eventually causing permanent damage to the coatings. I've posted a pic of what it looks like. It's hard to remove because it is very sticky. There are a number of ways to treat it, which I won't go into here. Some people recommend cleaning the optics every session during high pollen season (which I personally do not like--cleaning is the most damaging thing you can do to your optics). Meade cleaned my corrector when I had to send the scope back for a drive problem. As for avoiding this issue this year (with its record pollen counts) I am going to experiment with optical mylar to see if it can be easily made into a temporary cover for the optics while the yellow-green snow is falling in my forested neighborhood.