A friend of mine has this problem, too. He owns a A4000 and does
not run NetBSD. He gets a black screen when switching from PAL
Hires Interlace to A2024. Similar to what others said it does
not happen every time but almost. I myself have never experienced
this problem on my A2000 with A2024.

What about a classification of A2024 owners? State machine and os
version and see whether there is something in common.

Owner: Heiko Nardmann
Machine: A2000
OS version: 40.68 (3.1)
Problems: no

Now the machine of my friend:
Owner: Christoph Wilhelm
Machine: A4000/030 (now with a WarpEngine but I don't think that matters)
OS version: 39.?? (what's the one it is delivered with?)
Problems: yes

Ciao ... Heiko