Update Query Error

I've been agonizing over this all day! This is the SQL for the query that I built:

UPDATE [Compl P129 A3C] INNER JOIN MasterFundSch ON [Compl P129 A3C].LOANNUMBER = MasterFundSch.[Loan Number] SET MasterFundSch.P129OldInv = [OLDINVNUMBER], MasterFundSch.P129OldCat = [OLDCATNUMBER], MasterFundSch.P129NewInv = [Compl P129 A3C]!NEWINVNUMBER, MasterFundSch.P129NewCat = [Compl P129 A3C]!NEWCATNUMBER, MasterFundSch.P129PrinBal = [PRINBAL], MasterFundSch.P129PrinTran = [Compl P129 A3C]!PRINTRANS, MasterFundSch.P129Diff = [PRINBAL]-[PRINTRANS], MasterFundSch.P129RptDt = [Compl P129 A3C]!RPTDATE, MasterFundSch.P129ActionCd = [Compl P129 A3C]!ACTIONCODE, MasterFundSch.P129DueDt = [Compl P129 A3C]!DUEDATE, MasterFundSch.P129EffDt = [Compl P129 A3C]!EFFDATE, MasterFundSch.[REPUR SUB] = IIf([groupID]="FH",IIf(Month([fund dt])=Month(Now()),IIf(Day([fund Dt])<16,"N","C"),"C"),Null)
WHERE (((MasterFundSch.P129RptDt) Is Null) AND (([Compl P129 A3C].NEWINVNUMBER)=[MasterFundSch]![New Inv]) AND (([Compl P129 A3C].NEWCATNUMBER)=[MasterFundSch]![New Cat]) AND (([Compl P129 A3C].ACTIONCODE)="0000" Or ([Compl P129 A3C].ACTIONCODE)="0820" Or ([Compl P129 A3C].ACTIONCODE)="0077" Or ([Compl P129 A3C].ACTIONCODE)="0078"));


I'm getting records updating that are not one of the four Action Codes that I've assigned.
Help before I go crazy!