i recently tried installed java 7 on ubuntu 12.04 and i think i screwed something up

I followed the instructions given here.

First you need to remove openjdk for this run the following command from your terminal

sudo apt-get purge openjdk*
Now you can install Java7 by adding the following repository:

sudo add-apt-repository ppa:eugenesan/java
sudo apt-get update
sudo apt-get install oracle-java7-installer

Now everytime i install a new program i get the following error:

Download done.
sha256sum mismatch jdk-7u3-linux-x64.tar.gz
Oracle JDK 7 is NOT installed.
dpkg: error processing oracle-java7-installer (--configure):
 subprocess installed post-installation script returned error exit status 1
Setting up python-central (0.6.17ubuntu1) ...
Setting up python-eggtrayicon (2.25.3-11) ...
Setting up gmail-notify (1.6.1.1-1ubuntu1) ...
Processing triggers for python-central ...
Errors were encountered while processing:
 oracle-java7-installer
Error in function: 

However.The program seems to install and work just fine so it doesn't seem to be a problem preventing me from doing anything

So then i reinstalled openjdk by going:

sudo apt-get install openjdk*

But i still get the same error.

going:

sudo apt-get install oracle-java7-installer gives me the same error.

What is going on?

Please let me know if this is clear or not and ill try to explain my issue better