v3.3.5 / Auction House Scan / Very slow

Hi there!

My worldserver is running. Everything is working nice and smooth, but:

Scanning the auctionhouse using Auctioneer is very slow, even on LAN (Ping is <1ms). It is much slower than on other private WotLK servers.

What could be the cause?

There is no load to the server (neither on cpu nor ram or hdd).
I have the AHbot running.
My scan speed is about 6 auctions per second…

Any idea?