[Theme: Oxygen] Gallery problem

Hello everyone!

I’ve just started with WP.
I use Oxygen theme and few days ago I’ve found a problem
with image gallery.
The pictures on my website used to show up in “image browser/slider”
and it was default for this theme (I didn’t install any plugin or something) and now images are displayed without this browser.
I have to click “back” in my internet browser to go bak to the gallery
and again, and again, pic by pic…
link–> http://patatyipomarancze.pl/na-rowerze-2/bieszczady-2011/

Any advices…?

Adam

http://ww.wp.xz.cn/extend/themes/oxygen/