mac address not in mac table

[gallows]

I have a workstation that automatically is dropping all network connections (drive mappings) every now and then. I figured I would look at the port on the 4006 and see if there are any problems, and move the workstation to another port to see if this corrected the problem. I have done this in the past by getting the mac address of the workstation and looking it up in the mac address table. The mac address shows up in the arp table but not the mac adress table so I don't know which port the workstation is connected to. Is there any significance to this? I don't know anything about the mac address table, in other words, does it get refreshed on a regular basis or is it fairly static etc. As you can probably tell, I don't know too much about switches period)
Any help or suggestions is greatly appreciated.

thanks,
gallows