Depending on what version of epubcheck you are using width is not longer a legal attribute on a table td tag. Instead the spec calls for using css either as inline styes or in an external css file.
Here is one approach to fixing this by example:
Code:
<table width="100%">
<tr>
<td width="80%">Foo</td>
<td width="20%">Bar</td>
</tr>
</table>
The width attribute is no longer present in HTML5. Use CSS instead:
Code:
<table style="width:100%;">
<tr>
<td style="width:80%;">Foo</td>
<td style="width:20%;">Bar</td>
</tr>
</table>
Similar things are true for align attributes on a p-tag.
The correct way to handle this for html5 is:
Code:
<p style="text-align:right">
This way of handling it is correct for all html4 and 5.