Asking for help. Message error with xv6700.

[lengfengfly]

Hello dear everyone, I'm using xv6700, I've flashed the newest version of wm6. Everything is OK at the beginning, but recently I always receive an error message as follow when I sent a text message:
Pop-up window title: Messaging
Pop-up window content:Your text message cannot be sent.
error message title(I received one):Text Messages Retry
Relative content:
13521**33**(the phone number to which I sent message maybe months before)
(here is the old message I sent maybe months before)
Error Class: Temporary
Cause code:Noack

Message failed would you like to retry?

This error has occured many many times, and no matter I select Yes or No, this problem will come again someday. It's really boring!

What I would ask is: could I delete some temporary file so that the old message won't appear again? Where does it exist on earth?

Thanks so much for your kind help!

Mr. Jia