Duplicate Content Issue

Hi,
I believe my site is being penalized by Google, i have the .com and .co.uk both indexed on Google and the .co.uk redirects to the .com and appears twice in Google. I have been told that i should not block the one which was first indeed which was the .co.uk but we want to keep the .com . Can someone confirm that blocking the site which was first indexed is going to be a issue with Google??? And how the best way to get around this problem is??

Thank in advance

I'm not sure hte exact answer to your question but I have heard that Google looks down on redirects when they finally catch on that that's what your doing...

The problem probably has to do with the type of redirect you're using. Make sure you're throwing a 301 permanent redirect.

In PHP it would be like this: