Strange line with PPM Testimonial

Hi, I have just installed PPM Testimonial for the site I am currently building. It is great and I would love to use it, but for some reason I have this strange blue line appearing at the left of the testimonial text. I have checked to see that any formatting on the text has been removed and I have also checked to see if the line still appears even when there is no text. It does. Does anyone know how to fix this?
Many thanks in advance for any help.

http://wordpress.org/extend/plugins/ppm-testimonial/