Mozilla released Firefox 3.0.9 yesterday, fixing more than nine security flaws – some of which were termed critical, causing crashes in Firefox 3 and, occasionally, in Firefox 2. Some of the crashes corrupted memory.One of the issues dealt with JavaScript running in mail programs on Firefox and Thunderbird (which shares the Firefox browser engine). According to the company’s website: Mozilla developers identified and fixed several stability bugs in the browser engine used in Firefox and other Mozilla-based products.