Hi, i'm using subuntu server 7.0 and sugarCRM 5.0.0f CE installed with fast stack linux installer

I'm having a problem here, in users with 6.0 version for Internet Explorer the buttons for next page doesnt work, the user receives an error message at the botton of the browser (page error). In IE 7.0 i have no such problems,

my question:
there is any pre-reqsuisits for web browser in sugarcrm 5.0.0f CE ?