As botg said already, you have a case problem.
Doesn't work:
http://www.myxtrex.co.uk/trek001.jpg
Works:
http://www.myxtrex.co.uk/trek001.JPG
Either name the file extensions in lowercase or link to the uppercase extensions inside the HTML.
Doesn't work:
http://www.myxtrex.co.uk/trek001.jpg
Works:
http://www.myxtrex.co.uk/trek001.JPG
Either name the file extensions in lowercase or link to the uppercase extensions inside the HTML.