Clyde,
Thanks for the reply, I have made the adjustments you suggested, I have increased the length of the header to 850 and I have left the results for you to see as they are only cosmetic. The left side remains 'fixed' the right side moves out.

I use the same type of header at http://www.bikesforsale.net.au and http://www.livestockforsale.net.au and http://www.bwf.com.au also I used the patchshop header in the previous version of Zencart with SimpleZen template.

I will keep investagating