When creating a Google gadget that pulls data from an XML file, you will probably notice that the data doesn't update right away in the gadget even after you have changed the file. This caching behavior can make it very difficult to troubleshoot, and you'll probably want to shut it off while developing.
It took me a while to find this so I'm posting it here:

From Google's "Refreshing the Cache" instructions:

To make sure your gadget fetches fresh new content at least once per interval, simply specify a value (measured in seconds) for the refreshInterval parameter. For example:

// Fetch fresh content every half hour

_IG_FetchContent("http://news.google.com/?output=rss", callback, { refreshInterval: (60 * 30) });

// Fetch fresh content every 10 minutes

_IG_FetchContent("http://news.google.com/?output=rss", callback, { refreshInterval: (60 * 10) });

// Fetch fresh content every 30 seconds

_IG_FetchContent("http://news.google.com/?output=rss", callback, { refreshInterval: 30 });

// Disable caching completely and fetch fresh content every time --  !! Try to avoid using this !!

_IG_FetchContent("http://news.google.com/?output=rss", callback, { refreshInterval: 0 });

function callback(response) { ... } 

function displayBailouts(val) 
			{
			  var url = "http://thedesignspace.net/widgets/bailout-data4.xml";
			  
			  _IG_FetchXmlContent(url, function (response) {
					   refreshInterval: (0);
					    if (response == null || typeof(response) != "object" || response.firstChild == null) {
					      _gel("content_div").innerHTML = "invalid response "+typeof(response);
							    return;
							}//end if