Won't Let To Share Files In Homegroup

I have no idea why microsoft does such simple things through the ass, maybe to make people go crazy. Here's the problem:

I have wifi network setup, homegroup with my blueray dvd player, xbox 360, 3 other computers (all windows 7). on homegroup options, I check marked all options, video, music, docs etc to be shared, and also to be streamed.

I made 3-4 folders in my drive (f) to put all my stuff in there that I wanted to share, but when I right click either of the folders and go to "share with" they all are set to "nobody" and when I click "sharewith homegroup" at buttom of screen something blinks as if another screen opened for a second- but nothing changes, it stayes on "nobody". Nothing fixed this. Not replacing securities, not remaking homegroup, I mean i've tried 100 different things and nothing seems to work.

Funny thing, on my xbox/dvd player - 2 of these folders are visable and I can play files in them, although they are both set to "nobody" as well. But others aren't.