Thanks for your continued efforts on this. The registry fixes I posted appear to prevent the unneeded SQL Cluster resource failures and the attendant 19019 errors, but I have suspected the underlying issue has not been resolved.

We have systems using HP and 3PAR based SANs that have been effected by this issue (We may have some systems attached to EMC SANS that are affected but I am unaware of any at this time). With the application of the fix recommended by Microsoft tech the Cluster resource failures have stopped and therefore the Clusters are no longer on the front burner, as it were.

I am continuing to see evidence of Disk subsystem issues (VSS & VDS errors which are interrupting backups)

Systems have been checked against the respective SAN configuration Matrixes for HBA drivers/firmware, MPIO etc etc

We have been applying http://support.microsoft.com/kb/943295 against some of the effected systems and the Jury is still out, but I have the feeling that we are not out of the woods regards this issue.

I will be paying close attention to this thread.