Running out of ideas ... need help

I am very new to CSS and standards based design; but, I really want to learn.  Needing results quickly, I opened StyleMaster and used one of their templates.  I didn't change anything really, just reworked the graphics.  Proofed it in all the browsers in the house and was so proud of myself for having actually accomplished the task.  THEN - I asked friends far and wide to look at the site.  It does NOT display correctly in IE6.  All the content is displayed below the navigation column.  Using Dreamweaver I tried to find some clue; but none of the clues led to anything that worked to make it display correctly in IE6.  Works great in IE7 but Microsoft isn't forcing the upgrade so I guess it is a BIG problem for me.  Bad news is the client uses IE6. Can somebody look at this and give me a clue  to fixing it - I'm willing to try anything at this point.  Really hate to go back to tables now when I'm so darn close.  THANK YOU!!

http://moonflyacds.com