Apple and Adobe have known about this since version 1 of Xsan released in 2005, 7 years ago. Sorry man, but they are not going to fix it. I used to do deployments of Xsan professionaly and Adobe engineers told me directly, that its never going to be a priority as they don't want to re-write fragile legacy code for saving files for what for all intents and purposes are edge cases of people using Xsan/StorNext.
The only thing you can do that is surefire is work locally, and move files via the Finder and overwrite old saves.
I contacted Adobe about this and they are blaming Apple for this bug...