Webmin with Apache as pr0xy - http 500

[threetimes]

Short story:
Look here or here.

Long story:
I installed webmin, but from inside school, I can't acces anything an any port but 80. So I use my main Apache installation as a pr0xy for anything else. With ajaxterm, it works. With webmin I get a HTTP 500 (see links above).

See my httpd.conf.

As you can see, I used exactly the same trick as with ajaxterm, but webmin doesn't like it.
Why?

P.S. I can't use the word proxy in the title of this topic, because if I do that, I cant visit this page anymore. That's why I had to post this 2 times again...
Blame my school for this.

[threetimes]

The good news:
If you just go here, it works. So webmin itself doesn't seem to be the problem.

[drubin]

The good news:
If you just go here, it works. So webmin itself doesn't seem to be the problem.

Firefox can't establish a connection to the server at peter-server.homelinux.net:10000

.

are you sure you have port 10000 forwarded on your router?

If you do are you sure you school isn't blocking that port 10000?

[threetimes]

.

are you sure you have port 10000 forwarded on your router?

If you do are you sure you school isn't blocking that port 10000?

i removed webmin 'cause i don't like it