Permalinks only pls
I've noticed that many bloggers have been submitting their BLOG URLs as pings rather than the article PERMALINK.
PPS is programmed to ignore identical URLs i.e. the 2nd time the same URL is posted, it will be blocked.
Therefore, if you want your ping to get through, pls use the article PERMALINK.
Example:
Blog URL: http://www.yongkailoon.com/
Permalink to arcticle: http://www.yongkailoon.com/2008/05/12/blog-advertising-war/