the slide show uses standard image tags:
<ul>
<li><a href="_img/gallery/panel-fab1.jpg" class="p7lsm_type_img"><img src="_img/gallery/panel-fab1.jpg" alt="Panel fabrication 1"></a></li>
<li><a href="_img/gallery/panel-fab2.jpg" class="p7lsm_type_img"><img src="_img/gallery/panel-fab2.jpg" alt="Panel fabrication 2"></a></li>
<li><a href="_img/gallery/panel-fab3.jpg" class="p7lsm_type_img"><img src="_img/gallery/panel-fab3.jpg" alt="Panel fabrication 3"></a></li>
<!--<li><a href="p7lsm_img_1/fullsize/panel-fab1_fs.jpg" class="p7lsm_type_img"><img src="p7lsm_img_1/thumbs/panel-fab1_tmb.jpg" alt="Panel-fab1"></a></li>
<li><a href="p7lsm_img_1/fullsize/panel-fab2_fs.jpg" class="p7lsm_type_img"><img src="p7lsm_img_1/thumbs/panel-fab2_tmb.jpg" alt="Panel-fab2"></a></li>
<li><a href="p7lsm_img_1/fullsize/panel-fab3_fs.jpg" class="p7lsm_type_img"><img src="p7lsm_img_1/thumbs/panel-fab3_tmb.jpg" alt="Panel-fab3"></a></li>-->
</ul>
you could use image resizer on those image tags that are used by the slide show, and add a height and width attribute.
