User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; es-AR; rv:1.9) Gecko/2008052906 Firefox/3.0 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; es-AR; rv:1.9) Gecko/2008052906 Firefox/3.0 Its a bug inherited from Firefox 1, and Firefox 2. When saving web pages to USB Pen Drive, Firefox becomes so slow, that is totally unusable. Although it works best in Firefox 3, still is unusable. Reproducible: Always Steps to Reproduce: 1. Open any web page. 2. Connect an USB pen drive. 3. Save page to Pen drive. Actual Results: Firefox stop working or is too slow for a long time. Expected Results: Firefox need to stop working less than a second, or start a new thread, an take years to save the page meanwhile the user keeps using Firefox in paralell.