Header Size Not Correct for Logo and Its Being Squashed

Hi

On the following page http://forum.policecommunity.co.uk the logo is nicely placed and what I want to try and do is theme the front end of my website at http://www.policecommunity.co.uk the same with the logo but when I upload it to my theme it is all squashed and does not look right.

Could you take a look please Custom CSS plugin installed and also support access is granted.