Use of validation icon

Hi,

Just so I don't get off to a bad start I want to check if what I am doing is OK. My site (http://www.digitalofficeworld.com) is published dynamically and to get it W3c friendly I need to alter a number of factors in perl code software of the shopping cart that drives it. I coded the "W3c valid logo" onto the footer of the page as an easy way to check how I'm doing and how many errors have been reduced. 
When not working on the site I take this footer off (except on valid content) but reading the rules I see that use of W3c logo is very strict. 
Perhaps I can change the image to something like "transitional W3c testing" if this is not an approved way of testing a site but I do find this method very convienant.
Please advise how best testing via the logo can be done without breaking any rules.

Best Regards

Greg Molloy
http://www.digitalofficeworld.com