In beta 15, there’s a typo in the text below the ‘Custom file name pattern’ edit box in the ‘Options’ dialog box, ‘General Options’ tab. It reads as follows:
(Default is: %2n_%el_%bi_%fl_%su_%fn)
It should of course read:
(Default is: %tn_%el_%bi_%fl_%su_%fn)
i.e. %tn not %2n
Regards
John