This doesn't count as a reply, but I'm experiencing the same problem with Keynote. I had experienced it previously with iTunes 9 but I'd succeeded in circumventing it by deleting the firewall's preferences file and re-installing iTunes.
Unfortunately, reinstalling iWork '09, repairing disk permissions, deleting permission files and sacrificing goats has failed to fix the problem this time.
For what it's worth, I share your frustration.