The proxy is a domain account. Our DBA team has been logging the failures but has not been able to resolve them yet. As you know, error messages from Microsoft can be pretty cryptic and often read as if they were written for the people who develop their software as opposed to the people who use it. Even our DBA team has had trouble deciphering them. They've talked about involving Microsoft support (we have a contract) but I don't know whether they have done that yet. This thread was my attempt to see how well known this type of issue might be.