I had to perform an upgrade from the 6.6 CD
after the 6.5 version stopped booting.
Everything is now back to work.
Here is the fresh dmesg.
The only imperfection is :
"Tearfree" X.org configuration is required whereas
it wasn't on my previous OBSD install. YouTube videos are
also very twitchy and seem to be heavy on the system resources,
which used not to be the case.
I use xfce4-desktop on an independently assembled Linux laptop.