Operation failed my phone keeps displaying the message operation failed when trying to open inbox, outbox, drafts, sent items, it says failed when tryin to send a message, and wont let me recieve either

SOURCE: operation failed

This is normally a sign that the firmware is corrupt - back up the data in the phone to the memory stick, and then run the SE update service program on a PC and reinstall the phone software (if it says "you already have the latest firmware", then select "reinstall anyway")

The update service application is here:

http://www.sonyericsson.com/cws/support/softwaredownloads/detailed/updateservice/k850i?lc=en&cc=hk