OK, thanks - looks like Webmin is trying to use a fixed-width font courier that isn't available on FF 4. I will fix this in the next Webmin release (1.560).
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Which Firefox version are you running exactly, and on which operating system?
Im using Firefox version 4.0.1 on Windows 7 Ultimate x64
Here is an image to show what i mean, as you can see it should be half way.
http://img691.imageshack.us/img691/6109/progressb.png
OK, thanks - looks like Webmin is trying to use a fixed-width font courier that isn't available on FF 4. I will fix this in the next Webmin release (1.560).