if you open the msms gui you will see a Versions & Updates section with 'edit Schedule' link under the update now button. click the link to change the update schedule for the local update task. you can set it to not scheduled. the updates will then occur through the mcafee agent update task.
easiest way to roll back the dats is to go to the server that has msms installed, stop the msms service
open regedit to hklm\software\wow6432node\mcafee\mcafee portalshield\systemstate
set the datversion reg value to the previous dat that is listing in the msmsinstalldir\bin\dats folder
msmsinstalldir\bin\dats folder contains following folders
systemstate reg key
set value to 7242.0000
in the dat folder delete the 7243.0000 folder