First and foremost let me clear a few things up...
DNS is working both ways 100%. Netstat shows NO problems. Users log on fast with no lag. (Workstations are XP Pro SP1)
We have this problem with both a Windows 2000 Server AND a Windows 2003 Server!
IF we set the machine up as a standalone server with accounts matching those of the workstations, speed is very fast. Once we create the domain and have users logging in, the slowdowns start.
The slowdowns occur when opening a zip file with 200 small images, for example. Extract that to another folder on the users's share. EXTREMEMLY slow as in it takes MINUTES. If done locally on the machine, it takes 5 sec TOP.
When done through a mapped drive to the server (standalone) it's very fast like it should be. Now for the interesting part.
If I access the server by \\server\users\username\etc it's fast. Through the mapped drive it's slooooow. ONLY when the server is a DC.
Hardware...most workstations are dual Xeons 2.4GHz+ with 2~4GB RAM, SCSI, etc. Server is mid range Xeon MP with 6GB RAM, 12 15.3 RAID 50 etc. All connections are 1000 Mbps FD. File copy speed from WS to S and vice versa is 400~600 Mbps average. NOT hardware related! Speeds only drop when server is a domain controller! Very strange. I've searched the newsgroups and have found people having similar issues but there seems to be no real solution. This is ridiculous. We bought 2003 Enterprise w/ 100 users figuring the problem would be fixed. (The server is VERY fast as a standalone) NOPE!