I have a working RTD Excel automation add-in similar to the one described [here](https://stackoverflow.com/questions/5397607/how-do-i-create-a-real-time-excel-automation-add-in-in-c-using-rtdserver). Intermittently, while attempting to load a sheet that includes this formula I get the following error:

> 
> Microsoft Office Excel is waiting for another application to complete
>  an OLE action.
> 
> 
> 

I have checked and unchecked "Ignore other applications that use Dynamic Data Exchange (DDE)" per some forum discussion (which I can no longer locate). Neither works.

Google yields many hits for this error but no resolutions. There is an [ancient knowledge base article here](http://support.microsoft.com/kb/112030) but again no resolution.

What is causing this error? Is there anything that I can do to avoid it?

Thanks!