Other GUI oddities page 6
I’ve long since given away my Acorn Archimedes, and barely used it, so I don’t know if the following is an artefact of emulation (and the RedSquirrel Tools for emulation support) or a huge bug in the operating system itself, but this meaningless dialog pops up quite often:

QuickTime 6 has some intriguing format support. Take an image, any image:

Save the image to both PICT and PNG formats, and zoom each copy in PictureViewer:
For reasons unknown, PictureViewer uses different enlargement algorithms for each format: resize for PICT and resample for PNG.
Since around Windows 2000, Microsoft gave everyone a places bar in common file dialogs. For convenience, they made it extremely awkward to choose what goes in that bar, and non-privileged users are banned from making the change even with TweakUI.
I set one of the items on my laptop’s places bar to \\SPIRE (my desktop computer, always running) which proved not to be 100% reliable:
Wait … what the hell? The two dialogs – both Windows XP and in screenshots taken within a minute of each other – don’t have the same toolbar button icons. The first one is showing toolbar icons from Windows 2000 and earlier. Weird.