The two suspects I have are sharebar http://wordpress.org/extend/plugins/sharebar/ and breadcrumbs navxt http://wordpress.org/extend/plugins/breadcrumb-navxt/

Perhaps if you install these you should be able to reproduce the issue – which I am confident is not with simple press!

My suspicions were actually leaning more toward a WP bug… I will find some time to try these.

I have seen previously some js errors thrown from sharebar… but dont remember what the issue was…