AshMash

So since I put in a new server so that we could have an actual work network for the macs Ive had so many bugs to work through - random users getting 'library needs to repair to run applications', keychain login constantly popping up, etc... I've gotten to the stage that these bugs are no longer a problem, however log in times can be very long - anywhere from 3 minutes to half an hour... That's IF users manage to log on, sometimes they just aren't able to. According to the endless amount of forums on this topic, this could be due to a number of problems: DNS, TCP/IP Stack, struggle to talk to SMB... Can anyone shed any light into this? Please only respond with actual advice/solutions

So I've recently got a network up and running for our macs. They are using a Windows Server 2008. I have an issue with some of the student accounts - they keep getting a message saying "OSX Need to Repair Library to Launch Applications". I'm given 2 options, cancel or repair. I have to put in admin username and pass to be able to click repair. No matter which option I choose, the message comes back a few seconds later. I have found that it is only happening with certain users, not the mac itself. I've ran disk utility to check permissions, everything is fine. Any idea what is causing this?