As if this ever ends:

My interns were telling me that the files they were trying to work on over my network they could not save, read only.

So I went to the folder on my imac that has all the folders I use over my network, changed the folder to allow everyone read/write. I click the little triange to appy to all enclosed items.
Now every file in this folder says: everyone read/write
So far so good.
But when I open the file on my laptop via the network, it command i says:
unknown (greyed out)- read and write
and below that: everyone - no access.
Any help appreciated. thanks!