Just four days after releasing version 2.0.0.10 of Firefox 2.0 to fix six known bugs, browser developers at Mozilla had to scramble push out another update - version 2.0.0.11 - to fix a new bug that caused problems when the browser was rendering "canvas" HTML elements.

The latest version was released on Friday, marking the first time Mozilla has issued to updates to the popular open-source browser in one week. Version 2.0.0.10 was released last Monday.

The most recent canvas problems were detailed last week by Mozilla, which said at the time it expected to have an updated version out by last Friday.

Canvas elements, which were first used by Apple in its Safari browser, allow website designers to dynamically render bitmap images in HTML. Firefox, Safari and Opera support Canvas natively; Microsoft's Internet Explorer does so with a plug-in.

All editions of Firefox 2.0.0.10 - for Windows, Mac OS X and Linux - break pages that include the Canvas element, and cripple at least two Firefox extensions, FoxSaver and Fotofox.

The new version of Firefox is available for free download on the Mozilla website.