Open Question: i have an LG KP500. It has an icon on the top of the screen like failed message but I cant see it in my inbox.?

i have an LG KP500. It has an icon on the top of the screen like failed message but I cant see it in my inbox, outbox, drafts. messaging tools. Why is it displayed but yet there is no failed message in my messaging tool? How can i remove that failed message icon? hope you could help me. thanks a lot.