Browsing through the latest Windows XP driver and firmware of Z3100 I found the firmware TR12-7.0.0.3-5 from 10 Feb 2009.
Before I update my Z3100 - is it running well?
PS: Smooth update via network without hickups.
However, the printer indicates the firmware version TR12-TR_7.0.0.3 without the last two characters "-5".