ORA-00911 error on insert

From: shankar (s_shankarn_at_indiatimes.com)
Date: 11/18/04 

Date: 18 Nov 2004 05:23:50 -0800

Hi,
   The below INSERT throws a Invalid character (ORA-00911) error when
done thru jdbc.
INSERT INTO E(expid,callattr,operator,callaval,ruleid)
VALUES(8,'CallType','=','Voice',20).

The same when done directly at the SQL prompt works !
Anyone got ideas ?
The schema is
CREATE TABLE Expression (
ExpId INTEGER PRIMARY KEY,
Operator VARCHAR(5) CHECK (Operator IN ('=','<','>','<=','>=','<>')),
CallAttrValue VARCHAR(64),
CallAttr VARCHAR(32) CHECK (CallAttr IN
('CallType','StartTime','EndTime','Bandwidth','SrcIpAddr','DestnIpAddr','SrcPhoneNum','DestnPhoneNum')),
RuleId INTEGER REFERENCES Rule(RuleId) ON DELETE CASCADE
);