To littlened

I once tried to use the update feature in webmin to add some updates, and it failed. I forget what it was that was being upgraded, but at that point, I simply resolved to use apt-get or the update manager instead of webmin. So...

You might try uninstalling it from webmin, possibly from the command line (sorry, never used centos) and then reinstalling via the normal way w/o webmin.

Sorry, I'm not an expert. I post this here so your post is still a "zero reply" and has a better chance of getting answered by someone who knows a better answer.

if you install web min with rpm ... in centos try with
it's all.