What if you add NOFILTER to your query:

SELECT f1, f2 ;
   FROM mytable NOFILTER;
   WHERE f1 = "111" ;
   INTO CURSOR mycursor

---

>I have REM the statement CURSORSETPRO("BUFFERING", 5) in my form, set form.buffermode = 0, and form.datasession = 2 (private). It still cause the same error if i SET DELETED OFF. I work fine if I SET DELETED ON my my form.