Mozilla/Firefox does not reload page marked "no-cache", if a user goes back in the browser session history.
Mozilla/Firefox reloads a page marked "no-store", if a user goes back in the history. This behavior is "as designed" for Mozilla, but have been broken for a while and was recently fixed in Firefox 1.0 RC (see Mozilla bug 252023).
Pages which are marked as "no-cache", but which are served over SSL, are always reloaded by Mozilla.
MSIE reloads a page in all aforementioned cases.
If you want to keep your pages in sync with Model while using Mozilla, you need to mark your responses as "no-store". Struts has the convenient setting <controller nocache="true"/> in struts-config.xml file, but it does not set "no-store" header, it sets only the following headers: