punisa - 2:26 pm on Dec 1, 2009 (gmt 0)

I experienced the same thing recently. Usually new sites turned up in matter of days and my last project took 3 weeks.
Further research revealed to me that the domain I used has already been used by someone 4 years ago.
Apparently it had a bad record, spam links etc.

I wrote to Google using reconsideration form and informed them about what I discovered. Nobody replied, but soon the site turned up in serps.