To bad i dident read this forum before i bought backupexec 11d to one of my customers, then i probably would have bought arcserve instead... Bought a BACKUP EXEC 11D WIN SVR + CPS CD, that was wat...
First, "ml bus" is probably for MultiLanguage Business Pack. SBS version is something like: SYMC BACKUP EXEC SBS PRM 11D WIN SMALL BUSINESS SERVER PREMIUM WITH CONTINUOUS PROTECTION SERVER, so you got the right version.
For serial number registration, my experience is that you have to wait for next day (24 hrs).