FFT megafunction,simulation,fatal error

Have spent time trying to get used to flow of new (to me) quartus/modelsim. (ver 11) About there now, and think I'm about there

However, attempting to simulate the FFT megafunction IP, using the test bench that is so kindly generated, I get the following error.

# Fatal error in Process memory at C:/altera/11.0/modelsim_ase/win32aloem/../altera/vhdl/src/altera_mf/altera_mf.vhd line 39614

which looks a bit out of my control?

Anyone had this or similar? Can anyone give me a nudge in the right direction? I'm a bit lost

(win xp,quartus 11)

Regards

Pete B