I know this is quite an old thread but maybe somebody could help me there 
The extension does not seem to work with my fresh 1.6.3 installation (build 20080319)
My mileage:
weblog name - portfolio
gallery name - gallery (quite an original one, I know 
custom field name - galleryid
My template:
{exp:weblog:entries weblog="portfolio" limit="1"}
<h2>{title}</h2>
{description}
{exp:gallery:entries gallery="gallery" category={galleryid} orderby="date" dynamic="off"}
<h3>Project Photos</h3>
<div id="photos">
<ul>
{entries}
{row}
<li><a href="http://{image_url}" title="{caption}"><img src={thumb_url} width="{thumb_width}" height="{thumb_height}" alt="{title}" ></a></li>
{/row}
{/entries}
</ul>
</div>
{/exp:gallery:entries}
{/exp:weblog:entries }
It doesn’t work. I mean, I can see the entry title and description but no images. Also I cannot see the <h3> header - so I think all the gallery tag doesn’t work in this case.
I’ve found out that the extension is pulling the gallery category id correctly:
{exp:weblog:entries weblog="portfolio"}
{title}: {galleryid}<br/>
{/exp:weblog:entries}
Results in
Test Entry: 5
If I manually give this category number to the gallery tag - it works (displaying the needed images):
{exp:gallery:entries gallery="portfolio" category="5" orderby="date" dynamic="off"}
<div id="photos">
<h3>Project Photos</h3>
<ul>
{entries}
{row}
<li><a href="http://{image_url}" title="{caption}"><img src={thumb_url} width="{thumb_width}" height="{thumb_height}" alt="{title}" ></a></li>
{/row}
{/entries}
</ul>
</div>
{/exp:gallery:entries}
If I remove the category=”{galleryid}” part from the gallery tag, I can see all the images from the gallery (not only those of the needed category).
I tried also removing the quotes and using category={galleryid} but it results in showing all the images from the gallery.
Any ideas anyone? Please!