date comparison

[jenkinsdjj]

why does this sql statement continually produce a syntax error (missing operator)?

("SELECT * FROM [" & AccountAction & _
"] WHERE " & ActualDueDt & " <= " & ScheduleDate) & _
" AND " & DeleteInd & " = 'N'" & _
" AND IsNull(" & CompleteDt & ") = TRUE " & _
" AND (IsNull(" & RescheduleDt & ") = TRUE " & _
" OR " & RescheduleDt & " <= " & ScheduleDate & ")" & _
" AND (IsNull(" & FAReviewDt & ") = TRUE " & _
" OR " & FAReviewDt & " <= " & ScheduleDate & ")" & _
" ORDER BY " & SchedulingParameterString)

I have checked the statement line by line and the problem seems to be associated with the comparison of dates ie <=. I am using vb .net 2005 and access 2003

thanks for any help