Attribute "BORDER"... but "border" was used

Hello to all,

when I was trying to validate

http://vip.travelbit.dyndns.org/galerie/mb_cl600/index.php

I got this error:

Validation Output:  1 Error
 1. Error Line 40, Column 59: Attribute "BORDER" is not a valid
attribute. Did you mean "border"?
 <a href="001.php"><img src="001.jpg" width="200px" border="0"
alt="Mercedes Benz CL 600"></a>

Doctype is HTML 4.01 strict - Source is:

39 <div class="galerie_left">
40 <a href="001.php"><img src="001.jpg" width="200px" border="0"
alt="Mercedes Benz CL 600"></a>
41 <a href="004.php"><img src="004.jpg" width="200px" border="0"
alt="Mercedes Benz CL 600"></a>
42 </div>

I guess, my code is OK. And if not, the validator should find the error
in all the lines. Bug or feature? ;-)

TIA 

Andreas Weiss