Well, in my opinion it's simply not a good idea to open any file (not just VIs or LV projects) directly from a network share. Many apps maintain temporary files and/or file open handles etc. in the source folder, and a network connection not only slows down such operations drastically but is a very "reliable" -in that sense- point of failure for this.
If you work on the projects alone and backup is the only concern: Work locally and set up a task that does automated copies from the local source to the network share, e.g. before you shut down your computer. There are loads of freeware tools and methods to do so on any platform.
If you work in a team and backup/source code control/versioning is the concern: Work locally, too, and get your work files by using an appropriate source code control tool. Again, there are loads of them.
Cheers,
Hans
