Error Code -2147221296 (0x800400D0)

Can anyone point me in the right direction for an explination of this code? I can't find any hits on it.

I have a VB6 sample app that reads a T-SQL script from a file and feeds it to SQLServer.ExecuteImmediate. All very pedestiran. When the script works it works great. When it doesn't, say a bad table name in a select, the function ends with Error Code of -2147221296 (0x800400D0) and a Description that indicates the error in some cases. In another case (a DCOM exe), the description is always "Method '~' of '~' failed". Does the caller being an out-of-processs class matter?

Is this a DMO code, a ODBC or OLE/DB code, a COM or OLE code, or what? I've been looking for this answer for a long time now. Any help would be much appreciated!

Additional info:

If I use Database.ExecuteImmediate instead of SQLServer.ExecuteImmediate then I get a real DMO error code...