XWiki loading problem

Hallo, I have problem with loading pages from XWiki (in Glassfish application server). Loading static files is fast (.js, .css, pictures in millisecond). Dynamic pages are showed fast too, but browsers (Firefox, IE, Opera) are waiting to end loading for 30 seconds. It terrible to wait 30 seconds to show WYSIWYG editor (because onLoad event). I tested with web tools then complete page is loaded for about 1 seconds (all js,css,pictures and ending html tag) but browsers are waiting (and looks like loading). It not only my problem but all computers in all department. I tested disabling cache and stats but no positive result. Has everybody same problem or experience with Glassfish? Thanks for any ideas. Zdenek Machac