If you are using an old version, you could try to update and see if it solves the problem.
It is possible that your issue is a bug solved in more recent versions.
EDIT:
I suggest you to carefully read theses articles about repositories, especially the explanations about third party repos.
http://ubuntuguide.org/wiki/Kubuntu_Precise_Repositories
https://help.ubuntu.com/community/Repositories/Kubuntu
While using external repositories, keep in mind that the software there could not be properly tested, can have stability issues and cause problems to your systems. Once you have read and understood how repositories work, to upgrade your software, I suggest you to enable the Kubuntu Backports repo, which contains the latest version not only to Akregator but of the full KDE software collection, so be prepared to download a large amount of packages.
An easy way to enable it is with the command sudo apt-add-repository ppa:kubuntu-ppa/backports
Which version are you using? I'm with 4.10 and the feed you linked works for me. – Sekhemty – 2013-04-14T21:56:52.477
I'm using 4.8.4 – Ofir – 2013-04-15T05:14:02.337
I since tried removing and re-installing - didn't help. – Ofir – 2013-04-15T21:05:01.627
At least some of the feeds (e.g. the one above) work in at least two other feed readers. – Ofir – 2013-04-15T21:08:09.943