40D Focusing Dots

[tastas]

I have a Canon 40D which I've been using for birds in flight.  It works very well with my 400mm 5.6 L lens.  Typically, I choose a focusing dot--usually the middle one.  (1 red dot in the middle and 8 dots around). 

Question: Why has the top dot begun to stay lit?  For example, I chose the center dot--it lights up but the top dot stays lit.

I can choose any of the focusing dots, but the top dot always stays lit with the one I choose.  Always two dots lit.

Can anyone out there in cleverland explain why this has begun to happen and how it may affect focusing? Thanks

[Waddizzle]

That sounds like a malfunction to me, if it is always the same AF point.  What about different shooting modes?  What lights up in Green [A] mofe?  What lights up if you select MF mode, and lock focus?

[tastas]

Thanks...i use manual. I checked a couple of other modes...Same AF point stays on. I'll check some more..

[ebiggs1]

" Always two dots lit."

Does the 40D still work?  AF is fine?  If, yes, ignore it as repair will likely be greater than a good, working, used 40D.

[tastas]

It still works.  Not sure if it lessens the focusing accuracy.  Thanks for the message.