this is most troublesome as there isnt any readily apparant reason for this behavior.

But there is. The answer's in the code of the link you PM'ed to me.

Delete the target=" " attribute

Line 143, change

<a href="http://www.boswellcompany.com/HOMEmarch.html" target=" " onmouseover="MM_swapImage('home','','http://www.boswellcompany.com/HOME White.png',1)" onmouseout="MM_swapImgRestore()">

to

<a href="http://www.boswellcompany.com/HOMEmarch.html" onmouseover="MM_swapImage('home','','http://www.boswellcompany.com/HOME White.png',1)" onmouseout="MM_swapImgRestore()">

I dont see "target" within that code.

Neither do I.

But that's not the code at the link you PM'ed to me - which definitely contains the target attribute.

<div id="container">
  <div id="header">

    <h1><img src="http://www.boswellcompany.com/BigBLOGO.png" alt="logo" width="120" height="120" align="middle" class="thrColElsHdr" /></h1>
  <!-- end #header --></div>
  <div id="mainContent">
    <h1><a href="http://www.boswellcompany.com/HOMEmarch.html" target=" " onmouseover="MM_swapImage('home','','http://www.boswellcompany.com/HOME White.png',1)" onmouseout="MM_swapImgRestore()"><img src="http://www.boswellcompany.com/HOMEred.jpg" alt="home" name="home" width="132" height="32" border="0" id="home" /></a><a href="Our Coopers.html" onmouseout="MM_swapImgRestore()" onmouseover="MM_swapImage('Image8','','http://www.boswellcompany.com/Barrels White.png',1)"><img src="http://www.boswellcompany.com/ REDbarrels.jpg" alt="barrels" name="Image8" width="132" height="32" border="0" id="Image8" /></a><a href="http://www.boswellcompany.com/_about_us_test2go2.html" onmouseout="MM_swapImgRestore()" onmouseover="MM_swapImage('Image6','','http://www.boswellcompany.com//About Us White.png',1)"><img src="http://www.boswellcompany.com/Aboutus.jpg" alt="about us" name="Image6" width="132" height="32" border="0" id="Image6" /></a><a href="Tools Page.html" onmouseout="MM_swapImgRestore()" onmouseover="MM_swapImage('tools','','http://www.boswellcompany.com//TOOLS White.png',1)"><img src="http://www.boswellcompany.com/ToolsRed.jpg" alt="tools" name="tools" width="132" height="32" border="0" id="tools" /></a><a href="mailto:staff@boswellcompany.com" onmouseout="MM_swapImgRestore()" onmouseover="MM_swapImage('Contact Us','','http://www.boswellcompany.com/Contact Us WHite.png',1)"><img src="http://www.boswellcompany.com/ContactUsRed.jpg" alt="contact us" name="Contact Us" width="132" height="32" border="0" id="Contact Us" /></a></h1>
  </div><div id="footer">