Believing I had a sync problem with the DCR, I zeroed the DFM database as detailed in another post here, ie
perl dbRestoreOrig.pl dsn=dfmInv dmprefix=INV
perl dbRestoreOrig.pl dsn=dfmFh dmprefix=FH
perl dbRestoreOrig.pl dsn=dfmEpm dmprefix=EPM
DFM was previously setup to only email me OperationallyDown objects using event set A with only 1018 ticked.
Even though I have recreated this, and only have Reachability Settings enabled for polling, I now get ALL reachability events.