For myself, viewing the site's root and browsing folders works, but when clicking on a .htm or .txt file, the Mozilla brings up the save file dialog. However, these text/html files show up inside the window when using Opera v6/7 and IE6.
This also happens when directly accessing images, and any other file formats which should be opened within the browser when plugged into the location bar.
On my system, this behaviour was present when I tested Netscape Communicator v4.8 and Mozilla v1.2 and new profile.
I assumed it could be an application/octet-stream content-type issue and tried messing a little with the MIME settings, modifying my served HTML files, and searching a little around the net, but I couldn't seem to find a workaround other than using another browser.
Can someone verify this, or is it just me?