Hitachi: Streaked Lenses ?

Hi -


I have a strange anomaly (or maybe not) with my Hitachi rear-projection: I didn't notice this until after I had it serviced and one of the things that was done was cleaning the lenses so it may seem obvious what happened but I am not sure based on the size of the streaks. Anyway, I only notice this problem when I am watching a High Def broadcast but there appears to be green diagonal streaks in the picture which are particularly noticeable when the picture is showing light areas such as a white background, the sky, etc.... There are 4 or 5 streaks the same distance apart like the tech used a cloth a wiped it across the lense...I am hoping that this is the extent of the problem and I can fix it myself by cleaning the lense but why would the streaks be green only and is cleaning the lenses something that I can do fairly easily ? and what is the best way to clean them so I do not end up with "new" streaks ? I know the problem isn't with the mirror as I cleaned the mirror myself when the tech had the back open...any help / advice appreciated ! Rich