Conflict with Grid-fx plugin

Website :
(I've granted you access)

Since update 1.5 of Appointment+... it generate false <p></p> in source code so CSS does not load properly.

When Appointment+ IS NOT activated :

When Appointment+ IS activated :

NOTE : This problem occurs only when I use shortcodes in pages [gridfx columns="4"]

But if I of I do it directly in the php like this echo do_shortcode('[gridfx columns="4"]') ; ... Everything is ok!

Grid-fx plugin :

Thank you.