Quote from msleeper on December 31, 2007, 1:14 pm

There's no way to make a true zero-gravity volume unfortunatly, things will always tend to fall downwards or upwards depending on the setting of your trigger_gravity. You can try using a trigger_motion_vphysics (not the right name I don't think), which is effectively a more robust trigger_push that handles all objects in the game and not just the player. You'll still have to play around with it to get it to behave exactly how you'd like though.