We booked through HostelWorld 20 April 09 to stay 22 May 09. On arrival the hostel was closed. We arrived late at night, which turned out to be quite unpleasant walking streets trying to find different accommodation. On talking to locals in the area, it appears we were not the first this had happened to and is becoming a regular occurrence!
We shared our experience with HostelWorld, who have been good. However, we are receiving daily abusive emails from the hostel because of this. If you could stay anywhere else in Budapest, I would!