My wife's I-130 application for her parents was the same.
Applied to Nebraska in May 2005. I-130 sent to California.
I think they are doing this since Nebraska Service Center is overburdened with applications and they are trying to spread them around to process faster.
In our case
Priority Date: May 25, 2005
Petition Approval: December 12, 2005
Affidavit of Support Fee Notice Sent: January 06, 2006
Affidavit of Support Fee Sent: January 09, 2006
Copy of Notice of Choice of Agent Received and Faxed to Parents: January 09, 2006
Affidavit of Support Fee Received: January 14, 2006
Notice of Choice of Agent (DS3032) Sent: January 15, 2006
Affidavit of Support Received: January 23, 2006
Affidavit of Support Sent: January 24, 2006
DS230 Fee Notice Received: January 28, 2006
DS230 Fee Notice Sent: January 28, 2006
Affidavit of Support Returned (Incomplete): February 7, 2006
DS230 Part 1 Received: February 13, 2006
DS230 Part 1 Sent: February 21, 2006
NVC completed processing, sent to Embassy: March 8, 2006
Will update as process continues