Another couple of ideas - has this problem just appeared, and if so, have you tried shutting down the game and restarting it? It's amazing how often that fixes glitches for me (fortunately). Also, if he doesn't have seeds in his inventory, is there anything else in his inventory that could be causing this? I don't know what that might be, but if he has anything at all other than the fish he needs for bait, I'd take it all out and see if that makes any difference. Did Simis or anyone else in your Dynasty go travelling recently? Just remembering all the nasty travel bugs I've encountered ... (and hoping that's not the case for you).