Few things are as intellectually stimulating as diagnosing a mystery, and then solving it.

That dynamic's been going down on BlackBerryForums.com.

The mystery was first posed by user "phaser63", who started an Unknown Icon When Keyboard Locked thread on Friday. He said that when he locks his BlackBerry 7750 (running BlackBerry Enterprise Server 4.0), an unwanted icon appears at the top left of the screen. Apparently, it looks like a sticky note with the bottom right corner turned up.

Further complicating the mystery, phaser63 seemed stunned ("Star Trek" reference, get it)? about the number that appears to the left of the icon. Apparently, that number is subject to change, but at the time phaser63 first posed this question, the number was"4."

Fellow Forums member "kieron" posted his thoughts, but then this morning, phaser63 got back with a new post saying that he determined the icon was an orphaned reminder to check something he had overlooked.

Here's how phaser63 phased out the orphan reminder:

• On his PC he went into Outlook and called up the By Category view of calendar/tasks;
• Right clicked on the column heading and chose Field Selector;
• Added a column for the Reminder indicator;
• Synched his BlackBerry and his PC;
• Removed the BlackBerry battery and waited 30 seconds;
• Placed the battery back in the BlackBerry. The "orphaned reminder" icon was gone.

"Of course, no more reminders," phaser63 notes, but "I guess that is a small price to pay to get rid of the minor annoyances.