Note: edited my numbers to be more grounded in reality.

San Diego median household numbers are skewed downwards for two reasons. First, many wealthy people don’t live in San Diego proper. Second, poorest families and households don’t own homes. Median homeowner incomes are higher than median household incomes.

http://factfinder.census.gov/servlet/DTTable?_bm=y&-context=dt&-ds_name=ACS_2006_EST_G00_&-CONTEXT=dt&-mt_name=ACS_2006_EST_G2000_B25119&-tree_id=306&-geo_id=05000US06073&-search_results=&-format=&-_lang=en

Median owner-occupied household income for San Diego county in 2006 is $78,150.