"respawning too fast"

[Alessandro Ghigi <ghigi@math.mit.edu>]

I have installed Debian Linux on my laptop (Dell Latitude). At the end of
the boot process there is a weird screen and the mysterious (for
me) message

Init Id "S" respawning too fast: disabled for 5 minutes.

Every some minutes (I haven't checked if they are really 5) the same weird
screen emerges and I have to press Ctrl-L to come back to the prompt.

Any idea?

Thanks
Alessandro