Index on Yahoo!

is there any reason I'm not indexed in Yahoo?

My site is 1 month old, and have a rather small site (Just promotes my item, the rest of the site is locked to just members)

Index Status:

Google 5/6 Pages Indexed
Bing 6/6 Pages Indexed
Yahoo 0/6 Pages Indexed

Weird...I'm using Bing/Yahoo! Adcenter ad advertise too...

Yahoo Site Explorer is showing about 350 backlinks so far...but my site isn't even indexed by them.

That is a little strange as Yahoo is usually quick to index... ping those pages and hit them with a bunch of social bookmarks.