Not sure this is a sure answer, but I recently experienced a similar event while snmp services was being installed. There is little to explain it other than this. The machines (plural) that were 'clustered' together both terminated the DTC and SQL Server 2005 processes. Once the SQL service was restarted, both services (snmp) run together with out any issues. Unfortunately we only have these 2 machines configured in this manner

We tried a repeat on a stand alone, and it did not cause the process to stop.