what is Couldn't find installable ISAM???!!!(編號：4917)

hi,
我建立一新專案 form1上配置data1, 和一個DBGrid1 (MS Data Bound Grid Control 5.0 sp3),
data1的Connect屬性為dBASE 5.0; DatabaseName屬性為C:RecordSource屬性為table1(我在c:\中放置一table1.dbf檔)
DBGrid1的DataSource屬性為data1,
執行後會出現"Couldn't find installable ISAM", 請問為何會如此?