How to debug bulk insert?

I have this code which doesn't cause any error, and actually gives message 'query executed successfully', but it doesn't load any data.

bulk insert [dbo].[SPGT]
from '\\sys.local\london-sql\FTP\20140210_SPGT.SPL'
WITH (
KEEPNULLS,
FIRSTROW=5,
FIELDTERMINATOR='\t',
ROWTERMINATOR='\n'
)

How can I debug the issue, or see what the script is REALLY doing?  It's not doing what I think it's doing.

All permissions, rights, etc are setup correctly.  I just run the code successfully with a .txt file.  Maybe it has something to do with the extension...

Knowledge is the only thing that I can give you, and still retain, and we are both better off for it.