It could either be a carrier related symbol or an alert from a third-party app. Try searching through all your apps. If you have no luck with that check your blackberry messenger groups, as they have odd symbols.
Alternatively, if you could flash your OS to get rid of it.
Posted from my CrackBerry at wapforums.crackberry.com
Posted from my CrackBerry at wapforums.crackberry.com
Not exactly sure, thinking it might be missed voice mail calls but that is usually yellow telephone (handset) icon with a number to the left indicating how many missed calls.