this is a nasty bug indeed
i had the exact same problem once
you must understand, the gnome applet uses a set of scripts called pm-utils
to suspend and hibernate etc
these in turn call on s2ram or s2disk.
these scripts use a list of known computer types in some xml list somewhere i forget where
instead of starting to find exactly where the problem is, there is a nice clean work-around:
create a config file: /etc/pm/config containing simply
this will tell pm utils to use s2ram directly instead of its own scripts.
more can be read @: