Steam Achievements and Modding

[Thanatosis]

Does anyone know how adding mods to a game affects your ability to get achievements in steam? I've been playing FNV on the PC for a couple weeks and really want to check out some of these mods, but after having trophies and achievements drilled into my head I would hate to permanently lose the ability to earn them. Anyone know anything about it?

[Meusli]

As far as I am aware (I have Fallout 3) the achievements do work on a modded game, most of them do not effect the main story line so they should be OK.