It's been over two months since I switched from i386 to amd64 (32 bit to 64 bit) FreeBSD, and there are still a number of irritations that I haven't fixed. One is that Emacs windows are positioned outside the display. I haven't found a solution for that; I suspect it's less a FreeBSD issue than an Emacs or X problem. But at least I've found one way to retrieve them when using fvwm2: select them via the WindowList menu, which will bring them back to top left:
I probably knew about this kind of thing decades ago, but I never found much use for it until now. It's also interesting because it gives exact details of the location of the window. I had specified 120x85-53+0, which on this screen should have translated to 120x85+1111+0, but instead I got 120x85+2263+0an offset of 1152 pixels. Is that significant?