According to Visa Bulletin August 2006 Item E, the situation may be worse.
E. IMMIGRANT VISA AVAILABILITY FOR SEPTEMBER
Immigrant visa number use is approaching the annual limits for the year in many categories, and the supply of numbers remaining for allocation is limited. Therefore, for September there is increased possibility of additional retrogressions of cut-off dates such as those experienced in August. Readers should not assume visa availability until the cut-off dates are announced. Categories which could experience retrogressions are:
Worldwide: Employment 4th
China: Employment 2nd and 3rd
India: Employment 1st
Mexico: Employment 3rd