Comment 2 for bug 41709

For my Dell D600, the the solution to this problem was to remove the kernel module "cdrom" before suspending, and then have it automatically inserted. You can do this by editing the file /etc/default/acpi-support so that the MODULE section looks like this:

# Add modules to this list to have them removed before suspend and reloaded
# on resume. An example would be MODULES="em8300 yenta_socket"
#
# Note that network cards and USB controllers will automatically be unloaded
# unless they're listed in MODULES_WHITELIST
#MODULES=""
MODULES="cdrom"

Now I can suspend at will. I suspect that in order to safely remove the CDRW/DVD module I should:

sudo modprobe -r cdrom

and then

sudo modprobe cdrom when it is reinserted, but I haven't tested that fully yet.