Don't forget that the data shown in the reputation panel is generated from cache and may not always be immediately up-to-date.
Votes are worth from 0 to 4 points, based on the reputation of the voter. I don't believe we currently have any members with a high enough reputation for a 4-point effect however, and I've also never seen a +/-2 from the system; I'm guessing this is a result of the carry-over from the old system, where there was a bigger gap between most higher-rated users and those on lower reputation.
Are some votes worth more (like 4 or 5 points)?
There's also your +1/day for logging in, which sometimes takes a few minutes to show up in the list of rep events.
I'll definitely make the time to check over yours and a couple of other randomly selected reputations to make sure they really add up properly though -- thanks for the report!