Of course it does, have you ever thought of the fact that your logo is an image? And google doesn't read the text of an image to determine your company name. I understand there is also the title, the domain, the text which has your business name but what about the all important h1 to h6 tags.
At Digerati Solutions we deliver HTML Cutup Solutions that don't just have images as buttons but actually as text. And when the page is loaded, CSS imports the image.
We haven't seen any CSS problems with browsers, only that a:hover tags may get mixed up and the button/image flickers on global hover attributes.
Chat to us about how we can SEO optimise your website to be true HTML in the eyes of google.