Help!!!

[THX_5.1]

Can anyone tell me why my front projector now has a yellow smudge visible on anything white? I use it a lot to watch HD content and play xbox 360 and the picture is phenomenal but three days ago I noticed this just off center. I can't notice it during normal watching but anything white it is glaring to me. There is nothing on the lense and I clean the filter regularly.
I got thirty people coming over for the super bowl and want my setup to look perfect.

 

[BMXTRIX]

Obviously, all you will hear is a best guess.

Mine: You own a LCD projector and the blue polarizer is starting to fail. This is a normal occurance with LCD projectors and there is not a happy answer to the solution: Send it in for polarizer replacement. About $500 quite often for this repair.

Maybe over at AVS there are some DIYers that really have this replacement down to a science and can clue you in on parts and what is necessary, but not likely by Superbowl Sunday.

As I said though - it's just my guess.