validation - HTML5 - header tag -

I was just thinking about the following code ...

  & lt; Table & gt; & Lt; TR & gt; & Lt; Th & gt; & Lt; Header & gt; & Lt; H1 & gt; ... & lt; / H1> & Lt; / Header & gt; & Lt; / Th & gt; & Lt; / TR & gt; & Lt; / Table & gt;   
 When I validate it with the W3C validator, I get two errors.  
 
 element header should not appear as a descendant of th element.  
 The element should not appear as the lineage of H1 th element.   
 but ...  
  & lt; Table & gt; & Lt; Tr & gt; & Lt; TD & gt; & Lt; Header & gt; & Lt; H1 & gt; ... & lt; / H1> & Lt; / Header & gt; & Lt; / TD & gt; & Lt; / TR & gt; & Lt; / Table & gt;   
 OK I did not find an error message. Is it a verifier inspection or is it really wrong in both codes?  
 thanks ...  
 b   
 
 
 this one It is described in the device:  
    :  
 
 Flow content, but no header, footer, The title of the content line, with sectioning material, or   
 simply flows the material without any other restriction.