The first thing to try is to upgrade your gallery to the latest version of SimpleViewer Pro (v2.1.3).
Upgrades are free within the same major version number so you can download the latest version from the link in your purchase email.
If you cannot find the email or your link has expired, please fill in this form to receive a new link.
Once you have the latest version, replace the 'svcore' folder in your gallery with the 'svcore' folder from the SimpleViewer Pro download package ('simpleviewer_pro_213/web/svcore/').
Also, update your embedding code with the new style found here.
Inconsistencies when viewing a web page in different browsers can often be attributed to HTML errors.
You can check your page using the W3C Markup validation Service and then fix any errors found.
I just created a test gallery (v2.1.3 Pro) and used your gallery's XML settings and my gallery runs OK so it is not an issue with conflicting settings.
SimpleViewer Support Team