[Plugin: J Shortcodes] White preview page and J Tabs

Hi all,
J Shortcodes is fantastic. Thank you to its developers.

I have a strange problem: when I insert a JTabs code in my posts, and then click on preview post, the preview page becomes completely white after some seconds.
Is it normal?

Thank you,

Andrea

http://wordpress.org/extend/plugins/j-shortcodes/