Making progress with my weird RB67.

Ok, I found out what you guys were talking about with the question I had
earlier about my multi-exposure thing not working on my camera. This
weekend I did a light seal repair job on the thing and with the exception of
those grooves by the pressure plate, I guess I'm done. I didn't do those
because I'm not sure they are supposed to have anything in them, but
according to this page, I guess they are.

http://home.att.net/~colgoff/cameraback.html

So anyway, last night I tested my work by putting the lense on "T" and
shinning a flashlight in the lense in a dark room. I didn't see any light
leaks. Then I was playing with it and with the back in the vertical
position I couldn't trip the shutter. I looked in the manual and on the
last page it said that you have to have film in it. I had an old roll of
practice 120 film so I put that in and sure enough it works, but only in the
vertical position. When I turn it to horizontal, I can wind the shutter and
trip the film all the time. So now I'm stumped. I looked at the pins and
all the connections but nothing is bent or seems to not work. This has me
puzzled.

So my questions are, do you...
1. Agree with the pictures in the above webpage that show light leak
material in those tiny grooves by the pressure plate? And wouldn't that
prevent the pressure plate from sitting correctly so that it would throw off
the focus?

2. Do you have any idea why my camera's multi-exposure prevention works with
the back in the portrait position and not in the landscape position?

Any help is certainly appreciated. Ric in Wisconsin.