The error codes are listed at the top of the BASS.H file (or .BAS/.PAS if you're using VB/Delphi)... #6 is BASS_ERROR_FORMAT. So that probably means that the soundcard can't record at 44100hz 16-bit stereo
, which is what the recording test tries to do
Try changing the BASS_RecordStart parameters (eg. use 22050hz and/or mono) in the example source code.