Could you write more about the map? Was it a new random, aor a massivly used full of factories?
Are you using the 120.170 beta version of IC2? That is lagging for me too. Before it ran smoothly.
server spec?
This probably won't fix anything, but try updating to the snapshot builds, at least .184, found here: http://ic2api.player.to:8080/job/ic2_lf/
(1.112.184+fixes some console spam)
i Tried 184 and 201 but i dosent helps.
Well, at least now you won't get (some) console spam 
QuoteRandom generated, we have allocated 2GB up to 3GB RAM, somethimes i get
the Message: Overloaded.... but the CPU Load is only 10% and RAM Usage
is Ok. We using [MC 1.4.6] Open Beta v1.112
Can i see your start-up script? I was getting that error at one point and found the problem there.
Nevermind, this was specific to loading forge.jar instead of the merged version.
How's your hard drive IO look?
