In going from 32-bit to 64-bit Trisquel, I reformatted the drive, so it was
basically a new install. Testing: I left the FRAMEBUFFER line as-is, and
tried the GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT" both with
and without the vt.handoff=7 parameter.
The behavior is as you describe. With vt.handoff=7, I'm seeing the combined
corrupted image for at least a good 7-10 seconds. Without it, I'm only
seeing the single corrupted image for an aprox. one-second flash when the
grub screen clears. I also tried the Ctrl-Alt-F6 and F7 test while
vt.handoff=7 was back in, and that worked as described too.
It appears that either the workaround of removing vt.handoff=7 doesn't work
under 32-bit, or I did it incorrectly. Since it worked for you under both
versions, I'm assuming the latter. Either way, it's working for me now.
