For the menu issue, simple enough to fix. The problem I suspect is with the <br/> tags. Remove those and modify the sideBarLinks class as follows (add display, change height, everything else the same):
display:block;
height: 30px;
As for the fieldset and legend, I'm not 100% sure what your end result will be, but if you start by setting margin and padding to 0 for the <fieldset> itself, that at least appears to make it match in IE and Firefox.
