Comment 2 for bug 576248

I ran into the same problem and found out, that the package in question and it´s dependencies are missing in Lucid but are present in Karmic. Somehow they have not been enabled. This is maybe a mistake (most likely) or there are issues not beeing (re)solved with Lucid.

Anyhow, here is what I did to make the apt-get installation running flawless :-)

Open:

  sudo vi /etc/apt/sources.list

Add at the end of the file following two lines

  deb http://security.ubuntu.com/ubuntu karmic universe
  deb-src http://security.ubuntu.com/ubuntu karmic universe

I then did a
  sudo apt-get update

Afterwards I manually installed, before Webgui:

  sudo apt-get install libpoe-component-client-http-perl

And after finishing I uncomment the two lines above

As a final step

  sudo apt-get install webgui

You can always, before installing a package, check if there will be problems coming up by issuing the command:

  sudo apt-get -s install <package>

There you will see, if there are dependencies not beeing resolved properly without installing anything.

BR
MM