"Not enough storage is available to complete this operation (0x8007000e)" error message when trying to create com object registered in COM+

We have COM component deployed in COM+ (Win XP) to interact with SQL Server.

All operations goes smooth and suddenly sometimes, creation of the COM component deployed in COM+ fails.

The CoCreateInstance fails with error message stating "Not enough storage is available to complete this operation (0x8007000e)".

The documentation in the link - http://support.microsoft.com/kb/890425 states that "only 256 unique interfaces can be called from one process to another".

I need more details on this statement of "only 256 unique interfaces can be called from one process to another".

The approach that we follow is that

1. COM component has one interface method which interacts with SQL Server 2000 and returns the data.
2. Some other COM component that is not deployed in COM+ will create this COM+ Component and call the interface method to get the data.

When we create the COM+ Object , one RPC call is triggered. Will this RPC call end once the creation is successful or will be live until the COM object is destroyed?