[Leica] Slide projector only focuses half the image

["Dan Honemann" <ddh@home.com>]

I've noticed that my slide projector (cheapie Kodak carousel with the
original lens) will focus properly on either the left half of the image or
the right half, but not both.  I remember someone else posting that their
projector did the same thing.

Is this a problem with the projector itself, with the lens, with the way the
slides are mounted, or some combination thereof?  If it's the lens, I'll
replace it with a Schneider or Leica.  But I don't want to invest in a new
lens only to discover that's not the culprit.

I'd love to have the fancy Leica carousel unit, but man, that's one
expensive piece of equipment!

Thanks for any help in advance,
Dan (who has grown very fond of giving slide shows)