The subscription doesn't work

Hello!
At me such problem has turned out.
When I subscribe for Article, the Blog, a theme in the Forum etc. to me the message on successfully made subscription comes. But at any changes in the signed themes of the notification about these changes to me don't come.
And only the Forum works well. On any addition of the message in the signed themes to me the notification regularly comes.
Prompt, please, where and what it is possible to look?