subsite with issues is http://shadowfax.on.ca/
SQL 356 • PHPv 5.4.40
Marketpress Version 18.104.22.168
When Marketpress is on then the 'Add Media' button stops working (clicking it produces no outcome) as does the ability to switch between Visual and Text mode for editing page/post content.
It also appears that all of the product prices reverted to $0 quite recently on this site ... I am guessing during a recent plugin update. This is all quite a large concern for me and for my client.