simulation of FFT megacore in modelsim

i have a problem in simulating fft megacore in quartus

i performed following steps

1. added all file generated by megacore wizard (ip toolbench) of FFT in quartus and compiled it successfully.(including .vho $_tb.vhd)

2. created a vector wave form file and added all signal using node finder.

3. Exported .vwf to .vht

4. Assignment>>EDA tool setting>>Simulation

5. in nativelink setting

>> Compile test bench (clicked test bench)

>> new

>>in top level module in test bench (<name>_vhd_vec_tst)

>> added .vwf(from step 2) file in testbench file

6. TOOLs>>EDA simulation tool

i am not getting any signal only straight lines in all input and output

i think i have problem in native link setting

plz guide me where i am wrong .