Hi do anyone here no how to fix this problem, Example I try test send a message to a friends. it show this error

SQL query error!
Error infomation:

[SQL]
insert into jcow_messages_sent (from_id,to_id,subject,message,created) values('1','3','hi','hi',1291713383)

[Error]
Duplicate entry '0' for key 1

You can get help by sending this infomation to us: [url]http://jcow.net[/url]

Then I login to my friend account but the message is there! that's so strange anyone here have a clue.

have you edit somthing in the dB?
this error means that you have the from_id as auto_increment,, so any time you want to send the message, it dows not change and you get the error.
look in wour db by myphp admin, and be sure that in:
jcow_messages_sent
id int(11) NOT NULL [b]auto_increment[/b]

P.S.
link montontv in your neetwork is broken

thanks I figure it out, but still doing same thing. I just give up and reinstall jcow. thanks by the way!