NTDLL.DLL problem using Automation

hav

Hi all,
I have created a client application in Navision that uses ATL COM automation.I have written a codeunit containing the foll function:-

OpenItem()
BEGIN
CREATE(JB, TRUE); //JB is an Automation variable of type Job

ITEMS := JB.GetIItems(Ordertype, JobNo); //ITEMS is an automation variable of type IItems

//do some processing

//clean up all automation variables in the order of creation
CLEAR(ITEMS);
CLEAR(JB);
END;

Note that in the above code Items is a non-creatable class. Hence the interface function GetIItems() internally creates an instance of Items
class and returns an interface pointer to it.

My problem is when i run the client application, it crashes randomly giving
error for NTDLL.DLL, which i suppose is a system dll.

I doubt whether CLEAR() fn. should be called for ITEMS automation variable.
I am clear about JB var. since i explicitly create it using CREATE() fn. but ITEMS is created by the COM component itself.

Any idea.

Pls help me ASAP.

Thanks in advance,