If you get upvoted on a question, then the question gets moved over to another site - the original site deducts it from your total but does not remove it from your daily limit.
(Picture taken whilst today button is pressed - this starts from my first bit of rep today 4/3/10)
The red line is approx at the time that this question was moved from SuperUser.com to ServerFault.com
I have clicked the today button and checked on Jon Skeet's reputation tracker, and they both say the same thing.
I guess the reason for this is either a bug or because I can undelete my answer and get the reputation - I am not really that sure and just thought it was worth asking.