Let me first thank you for being part of our community! We are happy to have you here and love to see you as an active participant. This short code usually comes from having the Name ID feature added on your account. If you have a 3rd Party Task Killer or SMS Application downloaded this can cause this issue to occur. If you do have either of these install, uninstalling will resolved the issue.
If you have any further questions, please feel free to reply to this message or contact any member of the staff. Thank you and have a great day!
- Alicia B.