by Mauno Korpelainen.
I visited your site and was suprised to see that some files/images are found but some are not...
For example in moodle.org h t t p s : / / moodle.org/theme/afterburner/pix/footer/moodle-logo.png shows 
but on your site h t t p : / / stmichaelsrc.sbcschools.org.uk/moodle2/theme/afterburner/pix/footer/moodle-logo.png shows 
On the other hand for example h t t p : / / stmichaelsrc.sbcschools.org.uk/moodle2/pix/moodlelogo.gif does render 
Are you sure that all files of moodle 2 package are in a correct place, particularly the sub folders of theme folder?