Im looking to upgrade from 1.9.1.8 to the latest version.

what do I need to watch out for as I would like to retain all of the data that currently exists?

An issue I am hoping is addressed with an upgrade is:

I am displaying my own basic java script/html content above the forum using the default.aspx page and lastly displaying the forum. I have provided a div section that will hide an show portions of the content above the forum. The issue is the postback is causing a page refresh and thus displaying the content that the user has attempted to hide previously

its pretty much looks like this:

Board Title and Pics
div begin
Some scripted output etc
div end
forum

im hiding whats between the div tags so the user doesnt have to scroll the forum each time they click a thread etc.

thoughts?