left column height

Any ideas how i can make the left column on this homepage extend to the full height of the content. it works for the category pages....
http://demo.lanegallery.co.nz/index.php

Don't you mean main column height? Your middle "content" column on the home page has the footer in it, so I think you need to compare the code from your category.tpl and your home.tpl files to see where you are missing some divs.
eg. div.bottom doesn't appear on the home page.

Click this link to trouble shoot your problem with the div and other issues
W3C Markup Validation Service