Thank you till for your help! Two issue have now presented themselves.
1) ISPConfig is displaying the following warning:
Server: server1.example.com (Debian Unknown)
State: info (0 unknown, 0 info, 1 warning, 0 critical, 0 error)
The state of your Hard-Disk space is ok [More...]
Your virus protection is ok [More...]
Your Mail queue load is ok [More...]
Your RAID is ok [More...]
Your Server load is ok [More...]
All needed services are online [More...]
The System Log is O.K. [More...]
One or more components needs an update [More...]
When I click on "More..." for the components in need of an update, the following is displayed:
Reading package lists...
Building dependency tree...
Reading state information...
The following packages will be upgraded:
2 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Inst sudo [1.8.3p1-1ubuntu3] (1.8.3p1-1ubuntu3.1 Ubuntu:12.04/precise-updates [i386])
Inst hdparm [9.37-0ubuntu3] (9.37-0ubuntu3.1 Ubuntu:12.04/precise-updates [i386])
Conf sudo (1.8.3p1-1ubuntu3.1 Ubuntu:12.04/precise-updates [i386])
Conf hdparm (9.37-0ubuntu3.1 Ubuntu:12.04/precise-updates [i386])
When I return to the server status page, I continue to get the same message as above. When I log into the shell as root, it doesn't inform me there is a need to update.
2) When I try to upload a file to the server via an upload form, I receive a 500 error. Perhaps the PHP/Apache2 limits have been re-instated? After the upgrade, I left all settings "as-is" as to not cause disruption.
Once again, than you for all the help and the prompt attention.