I had the same problem with upgrading fluxbox 0.1.14 to 0.9.9. I did #upgradepkg fluxbox-blabla fluxbox0.9.9blabla, saw the first package being removed, a whole bunch of error messages and a prompt. When I tried to start fluxbox, it didn't work. So I went to the Fluxbox site, downloaded the slack 10 package for fluxbox 0.9.10 and did installpkg, same result as aje. But fluxbox is working.