One annoyance was the prominence given to Windows Live Messenger as it runs as an icon in the taskbar. I don’t use it much and want it running without consuming that real estate. Easier said than done as none of the Live Messenger options seemed to support this.
One of Tim’s bumper list of secrets sorted that (see 28: run in Vista compatibility mode) putting Messenger in back it’s place in the system tray. There are 29 other “secrets exposed” in his post: