dear Michael,

thanks a lot for your detailed answer. even as this didn't solve my problem, i could learn something about the way MoI uses the RAM.
it already happened to me, when saving certain views as PDF, that i get a message that i'm out of memory. i was always surprised, since i have far enough RAM (32GB). and also the activity monitor didn't solve the mystery.
but actually i was not aware that MoI is a 32-bit program. well, this explains the issues with the RAM.
so i'm looking forward to the 64-bit version.

in case i can solve the issue with different behaviour on different users, i'll post what i found out.
but i guess, i'm simply switching the profiles, depending on what i'm working on. that's not very elegant, but it hardly needs time and works for sure.

best regards:
_toggi