[jQuery] Double submitted ajax requests

[jQuery] Double submitted ajax requests

Very intermittently, I am finding ajax requests submitted with jquery are being submitted twice, once with parameters, and once without parameters. The code looks something like this:
jQuery.post("url?id=id",
                {param1: param1,
                  param2: param2,
                  id: id},
                  callback);
We are using jquery 1.3.1, and the error occurred most recently from a firefox 2 browser.
What we see on the server side, is a request with all the expected parameters, then about 200ms later, a request with only the id parameter. Does anybody have any idea why this is happening, and how to avoid this issue?
Thank you for any assistance!
Josh Ain
ITA Software