Hi Vincent,
I have exactly the same files plus four user files and I have not had to replace my lens (touch wood).

I have had another fiddle with the flare adjustment on my EX3, there is a choice of R,G and B which I guess refer to Red, Green and Blue. For a subject I used a red bodied pen with white lettering and for a lens I used a Nikon f4 300mm. There seemed to be a very small of red bleeding into one of the the white letters which I am sure was an artifact seen by the lens and not myself. Changing the R flare setting over its full range produced no observable change in the image on my 27" iMac. Admittedly I was only using an S-video cable so the image was not very good anyway. After all this I am none the wiser.

Are any of us wiser than the Sony guy who incorporated these adjustable settings in the first place. Maybe he doesn't know either, hence the lack of information.