How did you image these computers? NetRestore? NetBoot Install? Firewire cloning from disk to disk?

Did you modify the User Template folder in /System/Library/User Templat/English.lproj? If so, did you account for machine specific settings as stored in the ByHosts folder?

When you're logging into the systems, are you logging is a local user? As a network-authenticated user? If network, how are the computers in the lab bound to the network? Active Directory plugin in Open Directory? LDAP?

Are the computers and/or their preferences controlled by an MCX setup on an OS X Server, via Workgroup Manager?

As you can see, there are many ways to manage computers in a lab. Without knowing more about how your computers are being managed, it's hard to suggest what might be happening.

Ok, we're getting there.

When a user logs in, the OS authenticates against the LDAP database, determines that his/her home folder resides on the Unix server and not on the local workstaiton's HD, and so then works to either (depending on your setup) copy that home folder locally or maps the home folder to a mounted sharepoint. The latter is often called "roaming profiles" or "network home directories".

The Dock settings are saved in ~/Library/Preferences/com.Apple.Dock.plist. This file is part of the profile. However, Dock settings can also be pushed out from an OS X Server using what Apple calls MCX settings. You could use Apple's Workgroup Manager software, for instance, to tell a certain group of computers or users to have the Final Cut Pro icon in their Dock, while other users do not get the icon. The two settings "stack" in sense...so the OS will generate a Dock based on the settings in ~/Library/Preferences/com.Apple.Dock.plist and then add any Dock settings pushed out from the server, stored in /Library/Managed Preferences/username

But if you're not pushing Dock settings with Workgroup Manager, then that's just a datapoint that doesn't have any bearing on your situation.

Other Dock preferences are pulled from /Library/Preferences/com.Apple.dockfixup.plist. This file controls the "baseline" of what Apple will put in a Dock for a new user login. In Workgroup Manager, if you've turned off the option for users to be able to add/remove items from the Dock, then a Dock is generated by "mcx compositor" and the baseline Dock is ignored. If no user management is enabled, then the OS refers back to the baseline dock in the com.apple.dockfixup.plist file.

So, the real question here is: are you using OS X Server and Workgroup Manager to manage the settings on these lab computers?

You mentioned your using Radmind. Is there a chance you've pushed out an unclean loadset with a Dock setting in it, so the Dock settings in the loadset are overriding the Dock settings set by the user, or by WGM / MCX? I know I've certainly been guilty of not properly cleaning up my Radmind loadsets before pushing them out and then having unintended consequences--especially when i was first learning how Radmind works.

Could also be that the Dock settings are being cached somewhere. I'd have to look to be certain--I can't remember if Dock settings are once of the cached attributes of an OS X system. If so, then it might explain what's going on, as the computer is referencing a cache file instead of the correct Dock settings plist. Just a thought...