It would appear that some Nokia phones (Symbian S60) are susceptical to a DOS (Denial of service) sms message that will turn the phone into a very basic phone (read unable to support any kind of messaging, SMS/MMS). The damage is not permanent, but will require a factory reset.
Name of the vaunerability is; Curse of Silence
Good thing my cell is a Sony Ericsson C902 😉