To fix GRUB, I booted into Knoppix 5.1.1, opened up a terminal, did su to root and then the following (thanks to Kyle Rankin's excellent “Knoppix Hacks”; and yes, we all need a copy of this very valuable book)…
Read it here
Before I did anything, since things were already screwed up, I did a NetBSD 4.0 install to the SUSE partition. It wasn't the prettiest looking thing — the installer, that is — and I tried NOT to install a new Master Boot Record. But I did end up with one, and I booted straight into NetBSD. It looks exactly like FreeBSD when you start X. Twm is the window manager. And no, I still couldn't exit X from the Twm menu. I had to use ctrl-alt-backspace. So either Twm, or NetBSD and FreeBSD, do not like the $0 Laptop (Gateway Solo 1450).