Where's Paul Reid?  He made a comment in a seminar that he sees a higher failure rate for filled/plated over vias than for open ones.  I agree that your exact fill material and characteristics are needed.  While this process is well-known, the fill and the wrap are significant variables.  Good selection for the fill, good process control for the wrap.  And look at what heat has been applied.  Any rework?  For these parts or nearby?