Since upgrading to Windows 7, I've missed at least ten meetings (or have shown up 10 minutes late to them) because of the Windows 7 window grouping feature (which I normally love, by the way).
In Windows XP, the appointment announcements used to appear right in the center of the screen, on top of other windows when it was time to join a meeting, but Windows 7's flashing icon in the taskbar is not helpful at all. If you're actively working on a document, you're not going to constantly check your taskbar for meetings that upcoming/overdue.
The problem is widespread, many of my colleagues are also complaining about this. Although it may seem intuitive to MS that people are constantly checking their taskbar, this is NOT the case for everyone, particularly those who have documents open and are actively focusing their attention on them. The flashing icon in the taskbar is useless.
I am SO tired of my boss pinging me on MSN messenger to tell me that I'm late for our meetings. Can you please fix this? The problem is bad and widespread enough that third parties are writing programs to try to fix this annoying behavior!