Fow to fix styling issue with Appointments +

Hi

I have activated this plugin on a testing site before moving it a clients site, but when activated it is creating extra space to the right hand side of the site, (check the bottom of the screen for a horizontal scroll bar).

I have quickly gone through the CSS to see if I can find a conflict there that I could correct but no luck, and no errors are showing either?

I can give some admin privileges if needed so they can play around as this is a testing ground site.

http://jon.wixy.us/

Cheers