ODBCLINKSE does not allow multiple threads

[Thomson, Robert G]

We get this error when using Impromptu against an Image/Sql database. The
entire error message reads:

Query Server Error
Error number -239
DMS-E-GENERAL, A general exception has occurred during operation 'prepare
request with options'.
DMS-E-GENERAL, A general exception has occurred during operation 'start
transaction'.
[ODBCLN32.DLL]ODBCLINKSE does not allow multiple threads.

It's a query against a single dataset. We don't think we're trying to
multi-thread, but maybe Impromptu is doing something we're not aware of.
It's intermittent. We can duplicate it sometimes, but not always. 

If anyone can shed some light on this I'd greatly appreciate it.

Thanks, 

robert.g.thomson@boeing.com