What does HRESULT 0x80040012 (OLE_E_NOSTORAGE) mean?

My Google-Fu has obediently told me that the following error

Not able to perform the operation because object is not given storage yet (Exception from HRESULT: 0x80040012 (OLE_E_NOSTORAGE))

which is being thrown from a C++ function called in a C# project is, in fact, an error which is related to OLE. But I can't find much more beyond that - what might cause such an error, or what functions would return it.

More baffling is the fact that although I know the code I'm using has spat out this error before, I personally haven't been able to reproduce it. It's coming from a pair of unit tests, so I doubt that I'm missing some vital step to reproduce the error, unless it's due to some arcane machine configuration. Can anyone help me understand where it might be coming from?