I can't see what's going on, but I'd say you deleted the comments from your skin so they won't show.
From the original Nautica 2l skin I found in the _main.php file from line 194 onward:

<div class="bSmallPrint">
	<a href="<?php $Item->permanent_url() ?>" title="<?php echo T_('Permanent link to full entry') ?>"><?php $Item->issue_time(); ?></a>&nbsp;.&nbsp;
	<?php $Item->issue_date(); ?>&nbsp;.&nbsp;
	<a href="<?php echo url_add_param( $Blog->get( 'blogurl', 'htmlattr' ), 'author='. $Item->get('creator_user_ID') ) ?>" title="<?php echo T_('Browse all posts by') ?> <?php $Item->author() ?>"><?php $Item->author() ?></a>&nbsp;
	<?php $Item->msgform_link( $Blog->get('msgformurl') ); ?>&nbsp;.&nbsp;
	<?php $Item->wordcount();
	echo ' ', T_('words');
	echo ' . ';
	$Item->views(); ?>
	<?php $Item->categories('Browse category', ' . ', '') ?>
	<?php $Item->feedback_link( 'comments' ) // Link to comments ?>
	<?php $Item->edit_link( ' . ' ) // Link to backoffice for editing ?>
	<?php $Item->trackback_rdf() // trackback autodiscovery information ?>
	</div>

<?php // -------- START OF INCLUDE FOR COMMENTS, TRACKBACKS, PINGBACKS ---------
$disp_comments = 1;      // Display the comments if requested
$disp_comment_form = 1;  // Display the comments form if comments requested
$disp_trackbacks = 1;    // Display the trackbacks if requested
$disp_trackback_url = 1; // Display the trackbal URL if trackbacks requested
$disp_pingbacks = 1;     // Display the pingbacks if requested * pingbacks are going away!
// now get the feedbacks
require( dirname(__FILE__).'/_feedback.php' );
// ------------- END OF INCLUDE FOR COMMENTS, TRACKBACKS, PINGBACKS ------------

locale_restore_previous(); // Restore previous locale (Blog locale) ?>

</div>

<?php } // --------------------- END OF POSTS LOOP -------------------------- ?> 

It's quite a piece of code but you should inspect your _main.php to see if there are differences.

Furthermore, for the comments to happen there should be a _feedback.php file in the folder of your skin and a larger one in the folder ../blogs/skins/

Good luck

I have another thought. If you recently upgraded from 1.8.x to 1.9.x you might be working with a 1.8.x version of your skin. Then you'd better [url=http://skins.b2evolution.net/index.php?s=nautica&sentence=AND&submit=Search]dowbload[/url] the new version of the skin and apply the changes you made previously to the new one.

Delete the old skin, upload the new one.

Thanks for the reply, but, after reinstalling the default main.php for the skin, there are now no comments link displayed at all.
The install is a fresh one (new domain on bluehost, used cpanel install of 1.92). The feedback.php files are there, as expected.

Any more ideas?

given that other blogs work on the same engine and skin and site, how could i transfer all the blogs to a new blog, thereby rebuilding it?

I tried a fresh download of the skin (see link in previous post), installed it on my [url=http://blog.hemminga.net/a_stub.php?skin=nautica_2l]blog[/url] and it showed the comments link. You'd best try to update the complete skin, not only the _main.php file.
There are some major differences between a 1.8.x skin and a 1.9.x skin. I suspect part of your skin is old.

ok, it was a total reinstall of the skin,and is the version for 1.9.x but I'll try redoing it altogether. nautica info:
evoSkin: nautica_2l
Overall Skin Info:
nautica_2l 2 columns, fixed width, Colors: Blue Gray White
b2evolution Version: 1.9.* (skins are not expected to work with any version outside their own generation)
Skin design by: Studio 7 Designs
Other Design Credits:
Coded for b2evolution by: Danny Ferguson
Other Code Credits:
Updated for v1.9.2 by EdB
XHTML / CSS Validated? Valid XHTML 1.0 (Trans), Valid CSS2
Skin Features:
Archives Link? No.
Archives Listed (plugin)? Yes.
Blogslist? Yes - top.
Calendar Displayed (plugin)? No.
Categories Listed (plugin)? Yes.
Last Comments Link? No.
Linkblog? Yes.
Search Feature? Yes.
Skin Switching? Yes - list.
Who's Online? Yes.
XML Feeds? RSS 0.92, RSS 1.0 (RDF), RSS 2.0, ATOM 1.0 for posts and Comments, including inline RDF.

I was thinking this might have something to do with your subdomain usage, but now I'm not so sure of that. http://7doves.com/index.php?blog=1&skin=nautica_2l shows me that skin with it's "Leave a comment" link on posts, but not on the posts that show up on http://combatwombat.7doves.com/ - specifically notice the "Convert your Mint" post on each of these links.

So it's your blog setup. The blog using cw_stub isn't allowing comments.

Ok, I deleted the stub altogether. I also tried another skin, reflection, without modification barring the image. Still no go. I also got into phpmyadmin, to see if there was an obvious setting difference between blogs. Nope. Maybe I should figure out howto backup the blogs from mysql, remove that blog, and recreate it?

EdB suggests a blog setting.

Go to your back office (log in as Admin) and tick the Blog Settings tab. Near the end it sais:

Feedback options
Allow comments:
Always on all postsAlways allow comments on every posts
Can be disabled on a per post basisComments can be disabled on each post separatly
No comments are allowed in this blogNever allow any comments in this blog

The first or the second should be checked.

You won't be able to get the comments link with posts that are already published, but when you 'edit' an existing post, you can check the 'Allow comment' radio button on that particular post.

That's the trick for newbies, eh? You cannot comment on a post previously submitted , or one without the appropriate settings from b2evo's comments selection.

All my previous posts were from a Linux app called BlogTK.

The new post from the admin screen.

I added the last line bacause somehow you did manage to get the comments link on your test post. Glad I did.

:D you guys rock!

I've submitted a bug report at blogtk's sourceforge.