hi Michael,

I´m realy confused now - problem disappeared!
I cant even reproduce it anymore??

So: I´m working in MoI (units meter)
before export to ai, I changed units to mm - now I have a line lenght 10mm
export to ai (uncheck fit to page)
open in Illustrator CS3 (units mm)
-> wrong length! (line lenght: 70,556mm or 200pt) open in InDesgin all the same
so in MoI I found the decimal display is set to maximum - not much sense with mm, so I changed to 0,0!
export again: and everything is fine now! even when I change back, it´s stil working like expected now.
but changing the decimal display can´t have an permanent effect on export to ai, right?

anyway, all fine now - I´m happy
thanks for the concern and help
sorry for the trouble

thilo