Error compiling the standard niosII_cycloneII_2C35

hi,

i have a big problem when compiling my project:

error: node instance "ddr_control" instantiates undefined entity "auk_ddr_controller"

error: quartus ii analysis & synthesis was unsuccessful. 1 error, 49 warnings

error: peak virtual memory: 246 megabytes

error: processing ended: sun may 02 20:09:50 2010

error: elapsed time: 00:00:22

error: total cpu time (on all processors): 00:00:19

error: quartus ii full compilation was unsuccessful. 3 errors, 49 warnings

can any one help me to solve it;:confused::eek: