Counting explicit measurement error issue (bug?)

I can’t get explicit measurment errors to work with Dynare 4. The problem occurs in set_parameters.m on line 29, that goes:
offset = offset+estim_params_.ncx+estim_params_.ncn;

This yields a too low value of offset and I get an error msg for the next line:
M_.params(estim_params_.param_vals(:,1)) = xparam1(offset+1:end)
b/c the sizes of these two matrices are not the same.

The problem disappears if I change the first line (line 29) to:
offset = offset+estim_params_.nvn+estim_params_.ncx+estim_params_.ncn;

where estim_params_.nvn seems to contain the explicit number of measurement errors. Things would (maybe) have worked if ncx had been non-zero as well.

I just wonder if I create trouble / errors somewhere else by making this change.