Dave -- excellent sleuthing!
Do you guys not normally use keyboard shortcuts to switch between projects, adjustments and metadata panes?
Never. I use a high-resolution, programmable 15-button mouse (Razer Naga -- I love mine). Generally, while working in Aperture I keep my right hand on the mouse, and use my left for completely customized left-hand-only keyboard shortcuts. I made the decision to work this way because so much of what I do requires using the mouse that it made sense to buy a mouse with keys. (And I've done the same with the Wacom tablet.) I don't use shortcuts for most actions that I can effect with a single mouse click, preferring to save shortcuts for actions that are buried deeper in the interface or the menus.
This bug seems to have been fixed in the latest update to 3.4.4.
I've noticed another that's crept in though.... After importing from a memory card you get the option to delete or keep the pictures on the card and there's a check box to eject it but even with it checked it fails to eject the card leaving it mounted on the desktop.