I don't see how different file formats would make any difference. The difference between jpg gif png is just file size and image quality. They are all displayed the same on a website. If they are sending layered files such as ai, psd or pdf that would be a small problem, but I would be shocked if they sent you such files. What type of files did they send you?

You probably have a CSS problem, not an image/logo problem. but without a link or a better description of your issue, I can't be sure.

How about a link to the site? You are probably having a postioning/formatting problem most likely.

I think it would be best and more simple just to make a header that spans the length of your site correctly and have the logo super-imposed on the header graphic.

show us the picture and the name of the site so we can help?

Have you also used "firebug"?

It is a plugin for Firefox and can detect which issue it is...

Normally you have to use a logo image similar in size to the original logo/header that came with the theme (contact the designer if it is a custom build theme). Otherwise you'll need to tweak the theme's CSS to place the new image properly.

I believe it might be the positioning or size of the logo. Maybe its running off so it all cuts. Give us a link to the blog so we can take a look

Hi,
We can help you in that please contact me.

With Regards,
Fourways