Fiddle, perhaps, a recurrent problem for seer (11)

I haven't cracked this one yet — but the brilliant team at Times for the Times have:

NO STRAD (FIDDLE, PERHAPS: I think what the setter is getting at is that a Stradivarius is not something one would usually refer to as a ‘fiddle’, even if STRAD is indeed sometimes clued as a fiddle)  A SUM reversed (recurrent); I needed all of the cryptic to avoid falling for ‘Nostrodamus’, which has happened in the past.