Comment 23 for bug 424877

same here suspend with a sd card mounted in the left hand slot results in suspend freezing before it has completed.
i have also tryed the pciehp.pciehp_force=1 kernal cmd line option in grub2 with update-grup and backports. and this failed to resolve the issue, manualy unmounting the drive before suspend works, but this is a little inconvenient as forgetting to do so before shuting the lid will also result in a frozen suspend.

are you shure that the pciehp module is in the backports, i cand find it with modprob.

i will just sit tight for now and see if the next kernal update fixes things