Ajax problems in JQuery 1.4

When $. ajax () is used, I set the timeout time to 3 seconds:
Copy codeThe Code is as follows:
$. Ajax ({
Url: "ajaxTable1.aspx ",
Cache: false,
Error: function (XMLHttpRequest, textStatus, errorThrown ){
//
},
Success: function (html ){
//
},
Timeout: 3000
});

On the ajaxTable1.aspx page. sleep (1000*5); causes the page to be delayed for 5 seconds before execution. Therefore, the ajax request times out, but the error message "error: the object does not support this operation" is reported ", I thought I had a problem with the script, but I found no errors for a long time, and finally changed the JQuery-1.3.1 after the error disappears, the code runs normally. It seems that the new version is not stable yet.