I submitted my url to Google a month ago and had 10 incoming links of PR from 4-6 linking to it.It's even included in DMOZ. How come some of the urls which had only one incoming link of PR 6 indexed and not the other one?
You should read up on the Google quarantine aka sandbox (just don't let Brett hear you use the s word). Google appears to be aging sites and links. That is probably what is holding you back. You may need to wait 2-3 months.
In this case, I thought, your site has been indexed but your site hasn't shown the listing yet. You can check your site in google index by cache:, site: command in google search. There are many theories about google sandbox effect. From my suggestion if you would do on link building , you should not create a huge link back in a few days. It doesn't like natural link building.