Google Reader Api mark All item As read

This is how my url looks be:

https://www.google.com/reader/api/0/mark-all-as-read?s=http://www.campionatoseriea.net&ts=1345114937

I can't understand why it doesn't work! I'm successfully logged in.

* EDIT *

https://www.google.com/reader/api/0/mark-all-as-read?s=feed/http://www.campionatoseriea.net/feed&ts=1346843394

I tried also this query but it doesn't work!