Newbie Network Users Keychain Issue's

Thanks for taking a minute to look at my problem.

I'm an IT technician in a school and have just recently installed a new Mac Suite of 13x macs and 1x Mac Mini Server and i am having some issues with network accounts and the key chain.

Basically I have 200x Generic network accounts used for our music department, ie. Music01, Music02 etc.

Students don’t use iCloud/iTunes etc, mainly Logic Pro X,Pages and Safari

When users Log on they are greeted with " The System was unable to unlock your login Keychain” ~ “Continue Login " -Create New Keychain” – “Update Keychain Password"

If they click “Continue login” they will then be bombarded with password dialog boxed with all the various apps trying to access the login Keychain

If they Click Update Keychain password it will not accept their own password which has never been changed, but if I run through the list of users I will eventually get access to it which I’m assuming is the first user account logged in to that client that has created the keychain.

if they click create new Keychain the password dialog then goes away but then they don't have internet access due to our web filters SSL certificate not being installed which when configuring the machines I had added to the system keychain.

Server is Mac Mini 2.8Ghz i5, 8Gb Ram running Yosemite Version 10.10.4

Clients also running Yosemite 10.10.4 .

Also worth mentioning - when I log user, for example Music06 on and get prompted for the keychain password and try all the users passwords it will then accept Music02’s password then the tool bar above the desktop which shows music06 is logged in it will show “log Music02 off” in the apple menu and also show Music02’s home directory instead of Music06- apologies if that sounds confusing as if the two network accounts are merged together.

Thanks in advance for any help