When logging off and logging back on again after starting ODEX as a system service, the Event Manager actions are greyed out. How can I avoid this?

This can be resolved by adding "Full control" permission for the Local user called "SERVICE" to the following registry key:

"HKEY_LOCAL_MACHINE\SOFTWARE\Data Interchange Plc\ODEX Windows"

This can be done using the regedt32 program. 
This should only be attempted if you are familiar with the Windows registry and regedt32 program.