Many Free Directories Not Indexing New Submissions

I have been submitting sites to directories for a while now. I started by submitting to high PR sites that were referred by users on this and other forums. I received a very high percentage of my sites that were indexed in these directories.

Lately I have worked my way down to other PR4 and PR5 directories but have found that a very low percentage of my sites have been indexed in these directories. Since many of these directories are not overly crowed, it is obvious that I search

So, from what I have observed is that there are quite a few directories that are not adding new submissions. Anyone noticing similar results.

I have posted this on DP forum. Hoping to hear some responses.