Network manager forgets wireless password after sleeping or powering off

Solution 1:

I had the same problem. To fix this. Go to your network connections. From there click on wireless tab. Choose your connection and then click the edit button. Make sure your password is entered then click on the wireless security tab. Then check the box in the bottom left corner that says available to all users. This is what fixed the problem for me.

Solution 2:

Here is a slight variation of Hugo's answer. For me the problem was occuring with a particular network despite the "All users may connect to this network" checkbox being already checked. So what I did was to uncheck the box, save, check the box, then save again. I know this seems retarded, but it solved the problem for me.

Solution 3:

If you got the edit connections tab and look in wireless security. Is your password there. if not enter it and it should stay there.