dungeons and motion sickness

[Vodomir]

Don't know, which hardware and monitor setup you are running, but from what I've heard, running games at higher resolutions, wider view angles and at higher refresh rates and/or frame rates may help to ease the issues.

EDIT:
It may also help to increase the distance to your monitor and regularly lift your view away from the monitor, so your eyes also realize that you are in a stationary situation and not moving. (the sickness you feel is caused by conflicting sensory perceptions, your eyes report that you are moving in a fast elevator, while your equilibrium sense reports that you are in a stationary situation)