g77 compiler issues

[Usha Govindarajulu]

Hi,
  I'm trying to use the g77 program to compile multiple files:

g77 -o  make1 beta_est.f mat_mul.f dist.f dlam.f random.f run1.f
set_up.f simdata.f theta_est.f wn_est.f functions.f iidwt.f matrix.f solve.f
thiid.f  gsolve.f

And I get this error:

beta_est.f: In subroutine `beta_est':
beta_est.f:34: warning:
             CALL MATMUL(INVA,NPARM,NPARM,UU,NPARM,IONE,STEP,ER)

What can I do?  We haven't been able to resolve this one last error.
Appreciate any help.

Thanks,
Usha