I've just noticed I missed a comma out so try this

SELECT

count(Defect_Title),

tbl_Assembly_Holds.Record_Date

FROM

tbl_Assembly_Hold_Defects

join tlkp_Defects on tbl_Assembly_Hold_Defects.Defect_ID = tlkp_Defects.Defect_ID

join tbl_Assembly_Holds on tbl_Assembly_Holds.TagNumber = tbl_Assembly_Hold_Defects.TagNumber

WHERE

tbl_Assembly_Holds.Record_Date BETWEEN '8/12/2009' AND '8/14/2009'

GROUP BY

tbl_Assembly_Holds.Record_Date