If you need a new regulator you should search the forums for the one "Capo" recommends. It's a better regulator than the one Ducati purchases and fits.
And yes changing your exhaust around can cause issues. I just tried to tell someone this same thing about some slip ons they want to get but are convinced it doesn't matter.
09 Aprilia RS125 plated
06 Paul Smart Sport Classic NFS ever.
08 S4RS Tricolore #081 NFS ever.
01 M600, aka, The Pink Monster
97 900SS CR
72 Norton Commando 750
03 KX60 with S4R rear shock,Honda CB350F, Hodaka Ace90, 3x Yam-YGS1, Yam-CS3 200, Vespa small frame, Gilera 106, Puch Sabre, Puch 50 Boy Racer, Benelli 250, Benelli 360, Honda CB350T, and many more.