I am having a similar problem with my 97 ls (@81K). When starting in 1st gear from a stop, I get some chatter. 2nd gear and above show no symptoms. I can make the chatter disappear by "riding" the clutch in 1st, i.e. taking a bit longer from the point the clutch first engages until full engagment, but that's just going to wear out my clutch quicker. Any other ideas besides what has been metioned in this thread?

Ironically, I just had the timing belt and water pump replaced (200 miles ago), and the shop commented on my clutch fluid leaking. After the service, the shop had told me that my clutch master cylinder was leaking (I've known about this for some time) and that they had filled the resevoir because it was nearly empty. Could the timing belt/water pump service or filling the resevoir have anything to do with the clutch chatter?