Output differences between XML and JSON

I have been working on these APIs for a while and today I was surprised by a weird behavior of the following API call:

http://upcoming.yahooapis.com/services/res...amp;per_page=50

I was trying to retrieve "today's" events around Chennai, India. Guess, there are no events found and my JSON parsing was failing big time and I was wondering why. Upon debugging this is what I found. This call returned the following for XML

<?xml version="1.0" encoding="UTF-8" ?>
<rsp stat="ok" version="1.0" resultcount="0" />
- <!-- w1.up.re3.yahoo.com compressed/chunked Tue Feb 23 06:01:46 PST 2010
-->

The same with JSON call

http://upcoming.yahooapis.com/services/res...amp;format=json

Returned (2 quotes).

""

Can someone confirm if this is an issue from Yahoo side?