Issues reported to Sony included freeze-ups while trying to enter money into their PSN wallet, transactions showing up on credit card statements but not their PSN accounts and error codes while trying to download the Stimulus Pack.
Those having wallet problems are advised to wait a few hour and try again. Those with errant transactions will have to wait for the PSN to process said transactions. And those unable to download Modern Warfare 2’s DLC are simply being told to wait and try grabbing it during “off-peak” hours”.
PlayStation Network Issues Update [PlayStation]