In w3t.pm, find
<font color=blue>
print "Content-type: text/html\n\n";
print "<HTML><HEAD>";
</font color=blue>
and add
<font color=green>
print "<META HTTP-EQUIV=\"Pragma\" CONTENT=\"no-cache\">";
</font color=green>
That should do it <img border="0" title="" alt="[Smile]" src="images/icons/smile.gif" /> .

UPDATE: However, this should not be implemented until there is a better handling of the Preview and Spellcheck screens - with an edit area right there - because going back to edit will not be an option <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" /> !