So burst of force is a really cool spell, and I'd like to use it in the future, however, undead are immune to any fortitude effect that does not affect objects. Clearly this effect should affect objects, but it specifically affects creatures.
RAI this would affect undead, I mean they are not immune to force effects, but RAW they are unaffected is there a faq on this? If not can we get one, or is there another rule that clarifies that I'm not aware of?
Ask your GM. I would definitely allow burst of force to affect objects, and thus undead as well.