Ok, parts of this is solved:
You get errors and problems nowadays if you mount network shares with
anfstab-entry like the above.
The recommended way to use a network share is clearly to use places - connect
to share and set a bookmark.
Then you use the bookmark at first_access, when you need it.
I just found an important additional piece of information:
I unmounted the share and mounted it again, but not with the fstab-
entry, but instead via "Places" - "Network" - "Windows Network" -
"Workgroup" - "Servername" (and rightklick there the share)
In this scenario GEDit and Bluefis work. I a
