It's indeed the 16 color icon.... This means something has screwed up your msn messenger resources (a skin?) or something else is wrong. Try restarting msn messenger. If that doesn't solve it, try to repair it. If that doesn't solve it try to reboot. If that doesn't solve it redownload and reinstall msn messenger. If that doesn't work, though luck
Ps: please do not use BMP graphics to attach an image to the forum, they are rediculus big in size and the same image can easly be saved as JPG, GIF or PNG!!! Also why the big picture if all you need to show is the small system tray? Again a waste of bandwidth, especially when you use BMP's? see my attachment and the image size difference and especially the file size difference.