I recall one of the users stating a reboot didn't fix it. I'll have to do a test to see if the times are the same throughout.

I recall a user telling me that at reboot did not fix anything. Good point on the systems time and date. I'll verify that that is correct for the machines.

You should really try and confirm if Kerberos is being used on your network.

Can you confirm if your are using a Unlimited Client Licence version or 10 client version of OS X Server. You can find this out in Server Admin.

Has moving to AFP helped ? If so move all the client machines ( if you have unlimited licence ) to connect using AFP, IMHO preferable for Mac Client machines connections to OS X server anyway.

Thanks for all the help. I had a control group with the same configuration that had been having issues and then had two other groups, one using SMB and the other using AFP with both groups have a mixture of staying connected and putting their computer to sleep, disconnecting and putting their computer to sleep, and shutting their computer down. Those using AFP experienced no problems connecting while there was about a 50% success rate in connecting to the server with those using the SMB protocol. I had those who were having problems connecting switching over to AFP, and they had no problems connecting.

Thanks again and we can mark this as solved!

Agentx,

In response to your post, Kerberos is being used and we are using the unlimited Client Licensing. Switching to AFP appears to be solving the problem. Thanks!

So, the fact you have the idle and sleep settings with AFP they keep the connection alive where SMB probably kills it, thus never updating your kerberos tickets.

Just a guess, but sounds like you are on the right track. good luck with your macs.

All good happy days ;-)

So i would also advise all your machines sync with your local NTP server or all computers use the same external time clock.
Kerberos does not operate very well with non synced clocks.