googlereader.blogspot.com/2010 ...

<<As of September 30th, we’ll be turning off track changes in Reader. While this isn’t a widely used feature, we wanted to let you know in advance so you can set up a suitable alternative (such as page2rss.com). Your previous updates will not go away, but you will stop receiving new updates from any custom feeds you have set up.

We apologize for any inconvenience this causes – and as always, please feel free to visit our help forum if you have any questions.>>

Never used it :-)

Damned I will have to list all my feeds using this tracker in order to remplace them