im not quite sure what does ubuntu uses to suspend, so this might not apply but its worth trying.
first, identify your wireless kernel module (google a bit, use lsusb, etc)
once you have identified the module, create a file called 12modules under /etc/pm/sleep.d and paste this text inside:
modify it to include your wireless module.
case "$1" in
rmmod <your module> #insert your module's name
modprobe <your module> #insert your module's name
then you have to make it executable for it to work
i had to do something like this in order to be able to suspend since the config line in pm-suspend used to ignore modules does not work for me.
what this script does, is remove the included modules before suspend, and inserts them later. during resume. hope it helps.
if this does not help, simply delete the file created.