When editing files on a (Windows?) networked drive I get "could not be saved" errors
Autosave is not working, you might not have sufficient permission on that volume. You should try rebuild the permissions or take the folder ownership using chown -R.

"… does not support permanent storage" means Versions is not working because the volume is not HFS+, it must be NTFS or FAT and you are using a protocol such as smb. 

Apps who aren't using Version and Autosave have no problems.
If you want to disable these look here.