I can confirm same "bug" in in 2.19.900 on windows xp home 32bit
With "Saved form information" option checked, CC delete "signons3.txt" file in my firefox profile directory. That's where password are saved.
Last version did not do so.
Maybe they should add another option "Delete saved password", so we can delete form information BUT NOT password.
Except this bug, great work Piriform!