[Leica] Light leak in M6?

["Doug Richardson" <doug@meditor.demon.co.uk>]

My M6 is making one of its rare appearances away from the Leica repair
department, so I took it to the Paris Air Show as my working camera.

Looking through the resulting photos, I'm puzzled to see that one just
three of the 73, there is a blue haze and general washed-out look on
the right-hand side of the frame.

Two of these were taken with a Russian 9cm f2 Jupiter, so I was
tempted to blame the lens, but the third was taken with my normal 5cm
Summicron.

All three of the pics in question were taken with a shade in place and
either in the shade or with the sun behind me, so I don't think it's
flare. The only other possibility I can think of is a light leak - but
if that was the case I'd expect to see many more affected frames given
that I had the camera around my neck and with the lens cap off for
several hours outdoors, and had about half a dozen lens changes
outdoors.

Can anyone suggest an alternative reason for the problem?

Regards,

Doug Richardson