http://www.greencardfamily.com/news/news2009/news2009_0103.htm

USCIS has announced that it is abandoning the current practice of processing family members as a group unless the applicants request such group management. Currently, when family members apply for naturalization together, unless every single member completes the whole process including fingerprint clearance, none of the members in the family group is granted a naturalization.

Such practice has caused delays in processing of the naturalization applications with the result that so many family members remain a hostage until the processing of each member of the family group is completed.

Report indicates that there are currently about 10,000 cases of such group management. Accordingly, the new practice will result in members of a family being naturalized at different times even if they submitted applications together.  http://www.greencardfamily.com/news/news2009/news2009_0103.htm