The problem is with the footer div which has a margin of 10px all around.
so just change your css for footer to
margin:10px 10px 0px 10px;
it has a margin of 0px in the bottom due to which the div was not touching the bottom.
did u check your site in all browswer , when i had look in IE 7, IE 6 it looked much different.
I just had a look at it on an older PC with IE6 and its all off. Now I know most of the methods I have used are modern but how can I satisfy both versions of IE by achieving the same result.
i think u shuld increase the height of
height: 695px; ( height:700px;)
for keep your left column text inbetween content div.