On Wed, 21 Jun 2006, Mark Davies wrote:
>>    * Did it resume and (mostly) work? Did it resume but the display adapter
>>      didn't re-initialize?
>
> Running basically the test script as given it appeared to suspend OK but
> failed to resume, just rebooted as normal (or maybe resumed and then
> immediately rebooted so the first thing I saw was the normal Dell BIOS splash
> screen and then boot switcher menu).

Please update to the latest sources, and try again. Before suspending, do 
the following:

   # sysctl -w machdep.acpi_vbios_reset=0

Does this solve the system rebooting problem? It does on my Latitude D600. 
You may not have video on resume; if not, let me know and I can give you 
some of the workarounds I have used.

Cheers,
Jared