ERROR: PleskMainDBException

[Traged1]

Clients are getting the following error when they click on the "Home" link from their PLESk control panel:

ERROR: PleskMainDBException
DB query failed: Duplicate entry '4-98-custom' for key 2

Additionally, an exception has occurred while trying to report this error: PleskMainDBException
DB query failed: Duplicate entry '4-98-custom' for key 2

0: C:\Program Files\SWsoft\Plesk\admin\plib\common_func.php3:211
db_query(string 'insert into `DashboardPreset` ( `name`, `type`, `uri`) values( '4-98', 'custom', '/plesk/client@/dashboard/')')
1: C:\Program Files\SWsoft\Plesk\admin\plib\class.Table.php:336
Table->update(array)
2: C:\Program Files\SWsoft\Plesk\admin\plib\class.cObject.php:333
cObject->update()
3: C:\Program Files\SWsoft\Plesk\admin\plib\dashboard\DashboardPreset.php:183
DashboardPreset->update()
4: C:\Program Files\SWsoft\Plesk\admin\plib\user\User.php:344
User->addDashboardRecent(object of type plesk__client)
5: C:\Program Files\SWsoft\Plesk\admin\plib\class.Form.php:502
Form->FastPrint()
6: C:\Program Files\SWsoft\Plesk\admin\htdocs\domains\domains.php3:279

Anyone got any idea's as to how we go about debugging this one?