Error on Delete a Client

[MSDaibert]

Hello,

When i try to delete a client, i receive this error message:

<b>Source:</b> Microsoft JET Database Engine<br/><b>Description:</b> Data type mismatch in criteria expression.
---------------------- Debug Info -------------------------------
0: C:\Program Files\SWsoft\Plesk\admin\plib\common_func.php3:249
com->execute(string 'SELECT id from report WHERE user_type='4' AND user_id=4', NULL null)
1: C:\Program Files\SWsoft\Plesk\admin\plib\common_func.php3:249
db_query(string 'SELECT id from report WHERE user_type="4" AND user_id=4', boolean false)
2: C:\Program Files\SWsoft\Plesk\admin\plib\report\class.ReportManager.php:454
ReportManager->removeReports(integer '4', integer '4')
3: C:\Program Files\SWsoft\Plesk\admin\plib\class.Client.php3:407
Client->remove()
4: C:\Program Files\SWsoft\Plesk\admin\plib\class.ClientsList.php3:400
ClientsList->remove(array)
5: C:\Program Files\SWsoft\Plesk\admin\htdocs\clients\clients.php3:60


The client doesn't deleted...

Any one can help-me????

The plesk instaled is 7.6.
Thanks.