Spacing Issues

Page in question: http://www.vbstartup.com/pdz/

Does anybody know why even though the code is the same on lines 134 & 136 and 247 & 249, there is more space at the top of the banner image than the bottom?

Also, does anyone know why does IE adds some space between the header/menu table and login bar table?

And, if you are still reading by this time, Opera seems to display the login boxes farther to the right than IE/FF... anyone have any ideas as to why this is?

NOTE: This thread is not a place to gripe about the use of tables... If you can help me, great, thanks a bunch! If you can't, don't just make a post saying that I shouldn't use tables.

Thanks in advance,
Nick