Relative node for insert not found

Hi experts,

I'm using a Tree Control and sometimes this error appears (I use Automation Trace) :

<309=Automation(Error):    *****************************ERROR OCCURED IN MODULE: [SAP Table Tree Control ]************************************************************************************************************
<309=Automation(Error):    PROGRAM_ID                 |MODULE_NAME                 |METHOD_NAME      |ERROR DESCRIPTION                      |VERSION           |GUI VERSION        |MODULE_PATH                     |
<309=Automation(Error):    *******************************************************************************************************************************************************************************************
<309=Automation(Error):    SAP.TableTreeControl.1     |SAP Table Tree Control      |AddItemTable     |Relative node for insert not found     |6405.5.23.308     |6405.5.23.1024     |c:sappcSapGuiWDTTREE.OCX     |
<309=Automation(Error):    *******************************************************************************************************************************************************************************************
<309=Automation(Error):    

<309=Automation(Error):    Exception fire by :WDTTREE
<309=Automation(Error):    Exception info:Relative node for insert not found
<309=Automation(Error):    Exception code:0
<309=Automation(Error):                     Error occured at Verb  : AddItemTable
<309=Automation(Error):                                      Object: 15
<309=Automation(Error):    SAPAWRFC leaving RfcFlushOle with RfcRaise(CALL_METHOD_FAILED)

Can you help ?

Thanks for support.

David