Error: character ï not allowed in prolog
This looks like an extraneous BOM, but regardless, it can throw browsers into quirks mode:http://hsivonen.iki.fi/doctype/
Error: element a not allowed here; possible cause is an inline element containing a block-level element
This is a structural problem, and occurs several times. You're missing some closing </a> tags.
The maximum number of errors was reached. Further errors in the document have not been reported.
There are probably more errors (including structural errors) but the validator won't report them until you fix the other errors.