image include issue

I’m trying to add a logo on the header for the posts page of my wordpress site. I didn’t have a problem getting the logo to appear on the static pages, like home, but I’m having difficulty getting it to work for the portfolio section. This is how I want it to look…. http://www.mranymation.com/ This is what I’m getting…http://www.mranymation.com/portfolio ….. http://www.mranymation.com/category/animationportfolio/2d-work/raster

Also for some reason the portfolio page is the only page where the logo isn’t referencing properly not sure what that’s about. My code I placed in the header.php is as follows:

<link rel="stylesheet" type="text/css" href="wp-content/themes/arras/css/styles/mystyles.css" />
<div id="logoplacement"><a href=""><img src="http://www.mranymation.com/wp-content/themes/arras/images/MrAnymationLogoRaster.png" alt="Mr Anymation Logo" width="95.25" height="115.5" /></a></div>

Appreciate any advice anyone can offer