If anyone else wants to know how to disable any messages popping up as an X dialog, try this:
csRef<iStandardReporterListener> reporter = CS_QUERY_REGISTRY(
GetObjectRegistry(), iStandardReporterListener);
reporter->SetMessageDestination(CS_REPORTER_SEVERITY_ERROR,
true, //stdout
true, //stderr
true, //do console
false, //do alert (ANNOYING!)
true, //do debug
false); //do popup (default = false)
It's the alert part you don't want. Is it just me, or is the console enough of a notification?