Hola,
pásale los valores fecha en formato americano:
adostock.RecordSource = "select * from stock where sto_tip=1 and sto_fin= #" & Format(maskfecha.Text, "mm/dd/yyyy") & "#" adostock.RecordSource = "select * from stock where sto_tip = 1 and sto_fin Between #" & Format(maskfechai.Text, "mm/dd/yyyy") & "# And #" & Format(Maskfechaf.Text, "mm/dd/yyyy") & "#" 