Hello klh.
I believe that the problems you face are due to a wrong installation order.
The "FM Interior" mod should be enabled
after makman's mod. This way, when you enable the fix
after flakmonkey's mod, the cameras.dat file which is included in the fix and which has been adjusted for the "MaGui" mod, will overwrite fm's cameras.dat (which has already overwritten magui's own cameras.dat) and will ensure compatibility between makman's mod and flakmonkey's mod.
You have enabled makman's files after fm's own files thus undoing any changes fm's cameras.dat file introduced.
This is my opinion but wait for makman to reply too.
EDIT
I was
wrong. From the readme.
for those who want to use Flakmonkey&DD's ''FM_NI'' mod with MaGui 3.3
B. without Anvart's mods
------------------------
1.DD_OH_V3.09_20091209162038
2.FM_NewInterior_V1.0
3.MaGui 3.3
5.FM_NI_Fix_for_MaGui 3.3
Thank you comet.