yeah, Dreamweavers syntax highlighting does not seam very reliable at all.
For the tooltips, it looks like a title is not being added for some of the icons, i will log this to be fixed in a future update, in the mean time, you can add the tirtle tag manually.
for example, the dig link:
<a class="DiggThisButton DiggIcon" href="http://digg.com/submit?url=http%3A%2F%2Fwww.lovethisone.com%2Fsocial.php"></a>
should have a "Digg" title:
<a class="DiggThisButton DiggIcon" href="http://digg.com/submit?url=http%3A%2F%2Fwww.lovethisone.com%2Fsocial.php" title="Digg"></a>