I have a ThinkPad T42 at work. Usually it runs Linux (RHEL 4 AS), but once every 3 months I boot to Windows (XP SP2) to change my domain password (and to run Windows Update). If I knew a way to use SAMBA from Mac OS X or Linux to change my AD domain password, I might not boot to Windows as often as once a year! That would be nice, but unfortunately password changing isn't that easy.
I have an external monitor, a Dell 2405FPW, connected to it. Usually the monitor works fine. However, after I've booted to Windows, once I boot back to Linux, the monitor shakes. The scanlines don't line up anymore, and it looks for all the world like a hardware problem. However, if I unplug power to this monitor for two days (I haven't tested a shorter time period yet), it goes back to working. So Windows is doing something evil to my monitor that only shows up for Linux! Once the monitor has the shakes, it doesn't matter if I remove the BlackBox KVM or the Dock from the cabling.
I use the DVI connector to this monitor with my Mac OS X, and I use the VGA connector for the KVM and Dock (VGA KVMs are significantly cheaper!).
I'm still working on a theory to explain this, but at least I have a workaround, to leave it unplugged over the weekend.
UPDATE: a co-worker suggested that Windows detects the monitor, that also has card slot readers, and downloads new software (it would have to ask permission, and burn, new firmware, so I don't think it's technically firmware) to the monitor. Then when I go back to Linux, the new monitor software and Linux don't get along. It's a theory, but since I have a work-around (don't use Windows, or use a different external monitor with Windows, or leave it unplugged over the weekend), I'm not going to worry about it.