"Save As" Causes Spinning Wheel
So I did some basic troubleshooting and found that trashing the "ByHost" folder in my Preferences and then restarting solves the problem, at least for a while. Eventually, though, it comes back; then the only thing that works is to move "By Host" to the trash and restart. This seems to work every time. But then the problem always comes back sometime later.
I hope I have described this clearly enough.
Oh, yeah, I'm running a dual-processor G5 and I have plenty of RAM and hard-drive space.