with that kind of style-sheet (yes, I also convert from PG quite a lot) I cannot get the small-caps to show (desktop; XP; Calibre viewer) unless I add font-family: serif; to the declaration -- I used to need font-family: verdana, serif; until I updated to the "calibri, etc. pack".
Of course, I am using "default system fonts", and usually disable any others -- liking clear-type.
This is intended as a warning/request for information: is that a general issue ... ?
Of course, there are specific small-caps fonts, or font families with the variant included (I have found quite a few as freebies) -- but I should say many people, like myself, would rather stick to system defaults.