Header image going over margin

Hello,

After an update the image banner is either going over the margin or the blog is not respecting the margin.


I remember this happened before about a year ago, I searched and found a solution here. This time my google-fu seems to be not sufficient as I cannot find the fix.

If I remember correctly I had to replace a banner/header file.

Thank you so much for all you guys do,

Malenfant