Problem burning while using threads



I am using .net 2005 to burn CD. I have the following error when I try to call burning using a .net thread :
“Unable to cast COM object of type ‘System.__ComObject’ to interface type ‘NEROLib.NeroDrive’.
This operation failed because the QueryInterface call on the COM component for the interface with IID
‘{31928EE4-8847-49FD-9CD6-2B3D6BD073D9}’ failed due to the following error:
Erreur lors du chargement de la bibliothèque/DLL du type.
(Exception from HRESULT: 0x80029C4A (TYPE_E_CANTLOADLIBRARY)).”
And when I use the same function as a code behind a button it works correctly.
Any idea ?