Oh man, I hate ficing someone else's broken multi-level nested tables...
First suggestion: try using valign='top' on your table cells. That will fix one problem. As for the others, the approach I use in my own web designing when something like this happens, is to strip back the page to its bare bones and then start adding elements until something breaks. You can then more easily figure out what the problem is.
I'm sorry, but on such a complex page I personally don't have the time to go through it with a fine-tooth comb.
