That sounds like it's using the QuickTime plugin in both browsers. Firefox won't play anything in a QuickTime container natively. If you're using the native b

That sounds like it's using the QuickTime plugin in both browsers. Firefox won't play anything in a QuickTime container natively. If you're using the native browser video playback support (aka HTML 5 <video>), you should be able to seek anywhere in the video without a special server as long as the web server supports HTTP range requests, which is part of HTTP 1.1 and should work by default with most configurations.