cache control?

My javascript looks like this:

oTable.fnReloadAjax("/ducc-servlet/json-format-aaData-jobs",ducc_load_scroll_jobs_callback);

Using FF, about:cache show lots of entries line this:

http://myhost.my.domain.com:42133/ducc-servlet/json-format-aaData-jobs?_=1362577190455
http://myhost.my.domain.com:42133/ducc-servlet/json-format-aaData-jobs?_=1362577552438
...

where each entry has a different trailing number.

How can I prevent the browser cache from filling up with these non-reusable entries? I've tried several Cache-Control directive, but they seem to be ineffective (and not seen in the cache!).

Thanks.

Lou.