I had flushed memcached before i made my post here. I just flushed again and deactivate, uninstall and reinstall after cleaning up the db for swpm. still the same issue. The sandbox was unchecked. when i checked it, it has a notice that ask me to deactivate when im done. And when i uncheck and save, the notice was still there, until i saved the 2nd time, the notice changed to payment settings have been saved. I had also flushed permalinks, disabled supercache.