Mozilla is not hiding anything from you. You have nothing to fear in that department. That triple dot you see when viewing a long title is a bug. Want to squash it? If so you will need the Long Titles Firefox extension.
Here is what the author of the Firefox extension has to say about it.
Due to Mozilla bug 45375, long tooltips are broken with “…”. This is especially annoying if these tooltips contain useful or important information. Long Titles shows non-cropped tooltips for the title attributes.
Sure this is only a small fix for a small problem, but sometimes those are the problems that can eat away at you the most. One of the known bugs is that the tooltips disappear after a short while (normal Mozilla behavior). It is enough for small tooltips, but it can be a little short to read long titles. Move the mouse a little bit to make the tooltip reappear before a fix is found.
This Firefox extension is for versions 1.5 and up of the browser. To pick up your copy all you need to do is download it via the Mozilla Add-ons Web site.
[tags]firefox,extensions,tooltips,long,titles[/tags]