HTML code shows on mobile site

Looks like you have JetPack mobile enabled? Have you tried deactivating that to see if it makes a difference?

If not, have you tried deactivating all plugins to see if any others are causing that?

That may be a theme-specific question – in which case you’ll likely need to ask the developers of the theme as that appears to be a commercial theme?

It might also be related to a plugin – looks like there are MANY on that site, including NextGen Gallery, and there are quite a few problems with that plugin’s 2.0+ version – so you might look at that.

The other possible problem is that there appears to be spam/hack links in the header – look closely in the black portion – upon hover the link turns red. So you may want to check out these resources for hacked sites :

http://codex.wordpress.org/FAQ_My_site_was_hacked
http://wordpress.org/support/topic/268083#post-1065779
http://smackdown.blogsblogsblogs.com/2008/06/24/how-to-completely-clean-your-hacked-wordpress-installation/
http://ottopress.com/2009/hacked-wordpress-backdoors/

Additional Resources:
http://sitecheck.sucuri.net/scanner/
http://www.unmaskparasites.com/
http://blog.sucuri.net/2012/03/wordpress-understanding-its-true-vulnerability.html