I have x64 and it seems to be working.
what did you do to get it working? What os, card, drivers open cl sdk are you using?
working on x64 for me aswell, the only problem is that it finds blocks with a lower difficulty then the actual one, and I dont receive anything on my wallet,
my reaper primecoin.conf
host 127.0.0.1
port 9914
user user
pass pass
protocol primecoin
worksize 64
aggression 21
sievepercentage 15
sievesize 25165824
primecoin_address Axxxxxxxxxxxxxxxxxxxxxxxxx
debug false
opencldebug false
cpu_mining_threads 4
use_gpu true
use_gpu_fermat_test true
getwork_rate 4000
and reaper.conf
kernel reaper.cl
save_binaries yes
enable_graceful_shutdown no
long_polling yes
mine primecoin
#mine primecoin_testnet
device 0