Membership plugin conflict with my Theme and give different lay out in Firefox and IE

I have installed the membership plugin for my test site and my theme is ATTITUDE( Site look perfect on Chrome browser but in firefox and IE layout has changed .Pages created in the membership plugin(Account/Subscription/Welcome/Protected content) will be come automatically to home page widget area.Please advise me how to sort it out this .
My test site url is
appreciate your quick reply,
kind regards,