The file is called userdic.tlx, and it is specific to the computer you are on. So, if you add "resonance" on a computer, it is useful for that computer. If you still wish to have those words, you will need to go and find those files, which you may have written over.
As far as the other, it sounds like a permissions and/or security issue. When you share, make sure everyone has Full Control, Change and Read. And, under security, make sure that all users have read/write permissions.
