Mira a ver si se visualiza bien esto:
http://fdw.lohacemosweb.net/EjeImagenes.php
Lo he echo de la manera en el que te lo he puesto arriba y a mi almenos se me ve sin problemas.
Te dejo el bloque:
Código HTML:
<!-- inicio menu -->
<div class="menu">
<img src="http://www.maferelec.com/imagenes/m1.jpg"><a href="mafer.htm" onMouseOut="Image15.src='http://www.maferelec.com/imagenes/mafer1.jpg'" onMouseOver="Image15.src='http://www.maferelec.com/imagenes/mafer2.jpg'"><img src="http://www.maferelec.com/imagenes/mafer1.jpg" alt="mafer" name="Image15" id="Image15" width="42" height="49" border="0"></a><img src="http://www.maferelec.com/imagenes/m2.jpg"><a href="servicios.htm" onMouseOut="Image20.src='http://www.maferelec.com/imagenes/services.jpg'" onMouseOver="Image20.src='http://www.maferelec.com/imagenes/services2.jpg'"><img src="http://www.maferelec.com/imagenes/services.jpg" alt="services" name="Image20" id="Image20" width="64" height="49" border="0"></a><img src="http://www.maferelec.com/imagenes/m3.jpg" width="41" height="49"><a href="proyectos.htm" onMouseOut="Image14.src='http://www.maferelec.com/imagenes/proyects1_2.jpg'" onMouseOver="Image14.src='http://www.maferelec.com/imagenes/proyects2.jpg'"><img src="http://www.maferelec.com/imagenes/proyects1_2.jpg" alt="mafer proyects" name="Image14" id="Image14" width="104" height="49" border="0"></a><img src="http://www.maferelec.com/imagenes/m4.jpg" width="43" height="49"><a href="human_resources.htm" onMouseOut="Image17.src='http://www.maferelec.com/imagenes/human.jpg'" onMouseOver="Image17.src='http://www.maferelec.com/imagenes/human2.jpg'"><img src="http://www.maferelec.com/imagenes/human.jpg" alt="human resources" name="Image17" id="Image17" width="129" height="49" border="0"></a><img src="http://www.maferelec.com/imagenes/m5.jpg"><a href="news.htm" onMouseOut="Image18.src='http://www.maferelec.com/imagenes/news.jpg'" onMouseOver="Image18.src='http://www.maferelec.com/imagenes/news2.jpg'"><img src="http://www.maferelec.com/imagenes/news.jpg" alt="news" name="Image18" id="Image18" width="57" height="49" border="0"></a><img src="http://www.maferelec.com/imagenes/m6.jpg"><a href="contacto.htm" onMouseOut="Image19.src='http://www.maferelec.com/imagenes/contac.jpg'" onMouseOver="Image19.src='http://www.maferelec.com/imagenes/contac2.jpg'"><img src="http://www.maferelec.com/imagenes/contac.jpg" alt="contact" name="Image19" id="Image19" width="62" height="49" border="0"></a><img src="http://www.maferelec.com/imagenes/m7.jpg"></div>
Por cierto se te ha olvidado ponerles los id="", que eso suele provocar estos fallos.
PD.: Me gusta el diseño, simple pero directo al grano :)