[chriswatson]

OK i've heard back from vbseo and got it working

Step 1)

If you've already made the template changes for the highslide mod you only need to add the part in RED

Edit postbit_attachmentthumbnail template.
Replace:

<a href="attachment.php?$session[sessionurl]attachmentid=$attachment[attachmentid]&d=$attachment[dateline]"<if condition="$show['newwindow']"> target="_blank"</if>><img class="thumbnail" src="attachment.php?$session[sessionurl]attachmentid=$attachment[attachmentid]&stc=1&thumb=1&d=$attachment[thumbnail_dateline]" border="0" alt="<phrase 1="$attachment[filename]" 2="$attachment[counter]" 3="$attachment[filesize]" 4="$attachment[attachmentid]">$vbphrase[image_larger_version_x_y_z]</phrase>" /></a>

With:

<a rel="novbseo" id="att_$attachment[attachmentid]" class="highslide" onclick="return hs.expand(this, { slideshowGroup: '$post[postid]' })" href="attachment.php?$session[sessionurl]attachmentid=$attachment[attachmentid]&d=$attachment[dateline]"<if condition="$show['newwindow']"> target="_blank"</if>><img class="thumbnail" src="attachment.php?$session[sessionurl]attachmentid=$attachment[attachmentid]&stc=1&thumb=1&d=$attachment[thumbnail_dateline]" border="0" alt="<phrase 1="$attachment[filename]" 2="$attachment[counter]" 3="$attachment[filesize]" 4="$attachment[attachmentid]">$vbphrase[image_larger_version_x_y_z]</phrase>" /></a>

Step 2)

Manually enable VBSEO_ALLOW_REL_NOVBSEO option in config_vbseo.php file: (config_vbseo.php is in your includes folder)

Find-

define('VBSEO_ALLOW_REL_NOVBSEO',   0);

Change to-

define('VBSEO_ALLOW_REL_NOVBSEO',   1);

And after that the highslide hack will work with vbseo.