For some reason a number of the Yahoo inbound links keeps on decreasing slowly but surly despite steady manual link building. Any suggestions?
You might try some other tools to track inbound links. I use Majestic SEO and Open Site Explorer from SEOmoz.
Here are a few tools you can use to check for inbound links. http://www.seocompany.ca/tool/11-link-popularity-tools.html
I feel that you are not adding content yo your site regularly or the manual link builded are removed by moderators..
I have also noticed the same though i add content daily my yahoo inbound links have been decreasing in a great way.
Regularly update your site and do continuous link building. These should all be made daily and as much as possible consistently and manually.
I think its just temporary. Today all my links were reported back. The amount of yahoo links is back to normal and even my google links with even google finding 3k more so Im up to like 104k in webmaster tools so Im stoked. So just chill, my links were gone for about a week or so and now they came back. Hope this helps.