i think i know what you are talking about.

is it like hard water stains on your glass, that makes it look like it has millions upon millions of spots?

i think they are hard water stains. all my glass on my 240 has it.

so far, i have used the steel wool bought at walmart to try and rub the stuff off.

at first the glass is really rough, but the steel wool will eventually scrub it away.

LOTS of manual labor though. took me almost a week to finish it. i'm still not done.