Durst M805 Filters & Condensers issues

Hi,

I bought a M805. Everything in order, only two things bother me:

1. The manual says that the filter drawer takes 9x9 cm filters. I pulled the drawer out and frankly don't see how a 9x9 filter can fit in there, unless one just casually places it on top so that it rests on the outer edges.
There are two kind of metal supports inside the drawer, but to rest a filter on them I would definitely need to trim it. Must I trim them or not?

2. I've got all 3 condensers, BIMACON 80, BIMACON 75 and FEMOCON 50. BIMACON 80 works like a dream, the light footprint on the baseboard is perfectly rectangular, sharp and the light is even all around.
However, when I mount BIMACON 75 or BIMACON 75 + FEMOCON 50 the light footprint on the baseboard becomes weird, like a concave rectangular, and it darkens towards the edges. The centre seems to be lit evenly.
Is that normal?

If anyone has experience with these enlargers I would greatly appreciate some help
Cheers

did you change to the correct lens focal length for the condensor you had installed.

If filters are too big to fit in drawer then I think you have no ption but to trim them.

I did.

are condensors right way up?

Yes, they are...