v7.5 - SQL Server Native Client time column - Numeric value out of range error

[lasko.gustav@con-way.com]

When including a SQL Server time column in a report's results we get this error:
Error number -237:

DMS-E-GENERAL, A general exception has occurred during operation 'asynchronous open'.
[Microsoft][SQL Server Native Client 11.0]Error in row
DMS-E-GENERAL, A general exception has occurred during operation 'fetch'.
[Microsoft][SQL Server Native Client 11.0]Numeric value out of range
[Microsoft][SQL Server Native Client 11.0]Error in row
[Microsoft][SQL Server Native Client 11.0]Numeric value out of range
[Microsoft][SQL Server Native Client 11.0]Error in row
[Microsoft][SQL Server Native Client 11.0]Numeric value out of range
[Microsoft][SQL Server Native Client 11.0]Error in row
[Microsoft][SQL Server Native Client 11.0]Numeric value out of range

This only happens when using the SQL Server Native Client driver (all versions). Using SQL Server driver, the error doesn't occur (although separate bad behavior, namely that Impromptu doesn't send the filter to the database exists with that driver, forcing us to use Native Client).

Oddly, in the metadata, the time column is showing as a binary data type. Anybody seen this behvior before, and if so, have a solution?