Running the AGRIF_DEMO (release 4.0.1) the code violates the CFL (or similar) terminating with the following message:

===>>> : E R R O R
          ===========
 STOP
   stp_ctl: |ssh| > 20 m  or  |U| > 10 m/s  or  S <= 0  or  S >= 100  or  NaN encounter in the tests
  E R R O R message from sub-domain:            1
  kt=      76   |ssh| max:   20.89    , at  i j  :   135   12[[BR]]
  kt=      76   |U|   max:   4.294    , at  i j k:   133   12    1[[BR]]
  kt=      76   S     min:   4.538    , at  i j k:   148  127    3[[BR]]
  kt=      76   S     max:   40.58    , at  i j k:   154   92   19[[BR]]
        ===> output of last computed fields in output.abort.nc file[[BR]]

Checking the time step files I get the following:

time.step 76
1_time.step 76
2_time.step 304
3_time.step 912

This specific output has been generated using a single processor with gfortran however I did the test in two totally different architectures (both hardware and software) and I get the same results.