I have a set of attributes stored as a configuration, upon restart of the Orchestrator service some of these change into "Not Found".
Needless to say this causes some problems with workflows
I have found that if I edit the configuration element, but then close without saving (often takes 1-2 attempts) then the attribute value is back to how it was originally.
Is this a known issue in 4.2.1 on Windows?
I guess that could be related to your other question: http://communities.vmware.com/thread/402936?tstart=0
If the vCenter Plugin does not have the objects at startup-time, they are also not available in configuration elements.
However, that really breaks things! So my suggestion: Contact VMware Support...
Yes it is a known issue of vCenter plug-in in 4.2.1. See this : http://communities.vmware.com/thread/401052?tstart=30