I don't see where you would put a comma in that sentence.
.....
If you're using the DivX H.264 filter, make sure your decoder isn't buffering video a frame late ('to reduce effects of high cpu usage').
There should've either been a comma or the word "and" after "candy" since it's a list of two separate things that Sakura was doing.
Here's some more examples of where commas are needed:
Dialogue: 0,0:03:01.35,0:03:03.44,Touya,,0000,0000,0000,,Even so
, the stomping was noisy.
Dialogue: 0,0:03:06.10,0:03:07.66,Touya,,0000,0000,0000,,Just from you walking
,Dialogue: 0,0:03:07.66,0:03:10.25,Touya,,0000,0000,0000,,it sounds like a monster is stomping.
Dialogue: 0,0:07:45.13,0:07:47.08,Regular,,0000,0000,0000,,Opening the mouth into an O shape
,Dialogue: 0,0:07:47.08,0:07:49.81,Regular,,0000,0000,0000,,a boy{\fnVerona Script MF\b1\fs48}'{\r}s face became visible.
(And even with the comma, this sentence doesn't make sense.)
Dialogue: 0,0:15:19.20,0:15:21.80,Keroberos,,0000,0000,0000,,It is because of that
,\NClow himself made the book
Dialogue: 0,0:15:22.12,0:15:25.24,Keroberos,,0000,0000,0000,,and put me as the beast of the seal on the cover.
For the typesetting issue, I was using ffdshow and no subpicture pre-buffering in VSFilter.
Oh, and another thing I didn't catch earlier is that SMC is inconsistent about writing it as "Cardcaptor" or "Card Captor." They switch back and forth a few times.