Bluing at bottom of picture.

turn down the picture level the blue line goes away

if it is a dlp the light engine is going bad call sony and see if it is on their exstended warranty list.

bad optical block

Problem fixed by reading other post with same problem. Unfortunately Sony is not going to fix this problem.

Sony tech support (no charge) said it was definitely not the lamp.
Their suggestion- By unplugging the TV for a minute then turning back on, the blue color was substantially but not toally reduced.
Perhaps there is an electrical charge building up distoring the color by having the TV in the ready mode for too long and by unplugging, the charge dissipates?
No other phone solution recommended other than calling for repairs.

bad optic unit block

That's OK, I been provided you technical info about TV problem.

This seems to be common problem with Sony projection tv. I have the KDF-E50A10 that lasted only 2 years. It's sitting in a corner now until I figure out what to do with it. I am not going to spend another grand to repair it!! Never Sony again.

Sony wega blue dot or star pattern on screen
http://esupport.sony.com/perl/news-item.pl?news_id=206&mdl=KDF42WE655
Models: KDF-42WE655, KDF-50WE655, KDF-55WF655, KDF-60WF655, KDF-55XS955, KDF-60XS955, KF-42WE620, and KF-50WE620
Sony LCD Rear Projection TV - Optical Block Problems
http://splinke.googlepages.com/sonyrearprojectionlcdtv-opticalblock

This symptom is not related directly to the lamp.It looks dat the IC STK need to replaced.I think this must be remady of ur problem.