New Post: InvalidCastException when retrieving SupportedCaps capability

I'm using Saraff version, 1.0.20.517, with an HP Scanjet 8200 with official driver.

I am iterating on capabilities in order to retrieve the supported ones. In order to test if it is supporte I'm using:

twain32.IsCapSupported(TwCap.SupportedCaps)

I am getting:

InvalidCastException: Cannot cast from Saraff.Twain.__TwArray to Saraff.Twain.TwOneValue.

Is this expected?