It is probably still a very new prime so it will take time to go through the process and be updated on all webpages (I think the user account page lags from other pages).
According to the rules (Message boards : Number crunching : Unclaimed Primes) the prime checker has 19 days to respond and then you will become the discover. Of course, as a PPS it has already fallen from the top 5000 prime list.
If you search your name under the 'top prime finders' (see link under 'Leader Boards' on the left) you will see that you are currently assigned as a double checker for two primes. Actually it is probably this prime '1915*2^559802+1' since it is not on the top 5000 list.