Logo not positioning properly

Hi,

I am using Vantage and for some time the logo has been distorted, I have looked around and tried to sort this out but cannot seem how to. I have tried new logos and I still have the same problem.

The logo drops down and makes the menu bar a lot thinker, but sometimes if you refresh the page a couple of times it goes back to normal, its very strange.

Any help is appreciated.

Perry