Amaya bug? border-width: percentage

Hi

The following code:

<p style="border: red 3% solid">A red border around a paragraph.</p>

does not produce a border neither in Internet Explorer nor in Mozilla.

In Amaya a border is displayed, but only on the left and right sides of the paragraph.

CSS 2 recomendation says that border-width value may take one of
the following values: thin medium thick and length, so the percentage values 
seem not to be allowed.

Best regards,
Bartolomé Sintes