Im glad that you solved the problem. Here is what i found on ucoz forum.
Firefox is an advised browser from uCoz as it is especially useful if you download the uToolbar and additionally advised add-ons such as Firebug etc. It is not essenital however. In reality every browser except for IE is good for web development. IE is a massive irritation however most sites will need to be developed for cross-browser compatibility with it anyways due to 50% of the worlds population predominantly using it.