you dont, huh?
1. Your permalink pages ARE your single post pages.
2. The second link I plopped into the validator is a permalink page. Did you even look at the results, or just dismiss me outright?
Lets see, going down the list on this page:
http://validator.w3.org/check?uri=http%3A%2F%2Fwww.six-blue.com%2F%3Fp%3D30&charset=%28detect+automatically%29&doctype=Inline&ss=1
How many structural errors are there in your sidebar AKA your sidebar.php:
1. Line 82, column 10: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag .
2. Error Line 83, column 6: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag .
3. Error Line 119, column 6: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag .
4. Line 122, column 22: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag .
5. Error Line 124, column 6: document type does not allow element "li" here; missing one of "ul", "ol", "menu", "dir" start-tag .
6. Line 130, column 6: end tag for "li" omitted, but OMITTAG NO was specified .
7. Line 82, column 3: start tag was here .
thats 7 errors ALL in your sidebar, all related to how you have the lists.
Start at the top, fix them as you find them, and revalidate. Fixing one error above another might fix one below it.
have a great day. and maybe next time, read and think before posting. It's a time saver for those of us that take the time to help if you can do your part.