DCOM Servers suddenly stopped Loading

We have a client who have 3 servers - each running the same WWC 4.68 intranet servers (on 32-bit W2K3 Servers). There are two live servers and one test server.

About 2 days ago all 3 DCOM servers stopped loading properly or responding. The client _claims_ that no changes have been made to any of the 3 systems or the related databases. The WWC DCOM servers have been operating perfectly there for several months.

The DCOM settings have been completely reset on all 3 servers. The DCOM servers have been /unregistered and then /registered. A new AD account was also created and assigned to the DCOM identity. The Security of the DCOM servers has been set to Everyone has Local+Remote Launch and Everyone has Local+Remote Access permissions.

The servers operate _perfectly_ in File Mode when running under the same AD account that is assigned to the DCOM. In COM mode the servers do appear to start (they show up in Task Manager) - but they have a much smaller than expected memory footprint and do not respond and cannot be terminated using End Process. These unresponsive DCOM servers seem to shut automatically after a while but this appears to be because wc.dll is terminating them because they are timing out.

IIS has been restarted and the servers have been fully rebooted. The servers are 3 separate machines. Currently we have the Live system operating off a single machine running multiple servers in File Mode. The 2nd live machine is available to us for testing/checking.

These exact same servers and setups are in use at about 7 other sites without this issue.

The wcErrors.txt shows:

2012-11-20 07:39:13:888 Web Connection Request timed out. - ?atlas~start - 0
2012-11-20 08:32:28:836 Web Connection Request timed out. - ?atlas~start - 2
2012-11-20 08:32:28:836 Web Connection Request timed out. - ?atlas~start - 0
2012-11-20 08:39:02:138 An exception occurred in WC.DLL: _maintain~Load
Unloading all servers and reloading... - ?_maintain~Load - 0
2012-11-20 09:45:52:488 Exception in Loading Servers (COM) - 1008
2012-11-20 09:49:12:069 An exception occurred in WC.DLL: atlas~worksheetsavedoc~899219
Unloading all servers and reloading... - ?atlas~worksheetsavedoc~899219 - 0
2012-11-20 09:53:13:072 Exception in Loading Servers (COM) - 1008
2012-11-20 09:55:49:121 An exception occurred in WC.DLL: atlas~worksheetsavedoc~899219
Unloading all servers and reloading... - ?atlas~worksheetsavedoc~899219 - 0
2012-11-20 09:57:49:123 An exception occurred in WC.DLL: atlas~ps~platomain
Unloading all servers and reloading... - ?atlas~ps~platomain - 0

We've exhausted all our expertise on this. Do you have any thoughts on this and/or would you be available to assist the client at what ever your normal rates were (assuming you were available to do this)?

Thanks
Dan