Comment 27 for bug 614699

Alf, i used your repository as well, a simpler solution i found was this:
*delete your repository
* sudo apt-get update (or aptitude)
*apt-cache policy libqtcore4
*check the highest version in the version table available. at the moment of writing the post, this is 4:4.7.0~beta2-0ubuntu3~lucid1~ppa6
*order aptitude to install it using:
sudo aptitude install libqtcore4=4:4.7.0~beta2-0ubuntu3~lucid1~ppa6

aptitude will complain of dependencies, and suggest downgrading all packages from your repo, accept the solution.
if anyone finds any mistake/error/problem with this method, please tell me.