The event seems to be related to the protocols enabled in SQL when it gets installed. There is a technote related to BE here, http://support.veritas.com/docs/283949, which states it occurs without reason but won't effect BE function. The hang issue indicates to me that the connectivity BE uses to its own database was messed up by the install of Sharepoint. Since Sharepoint 2003 installs an older version of SQL, something related to SQL connectivity or MDAC may have been back-rev'd that broke SQL Express. It should be something easy to reproduce by Support if there really is a problem caused by Sharepoint and BE on the same server.
Russ