What do you mean by not allow? Does it produce an error or simply refuse to copy the CD?
As the previous answer said you do need to specify the 'type' to be copied.
lol, this question is 3 years old but just incase you havn't solved it and for the benifit of anyone reading through old questions the reason could be because the cd is copyrighted. The default for some cd burner software is 'no don't copy if cd is copyrighted'. On some it can be turned off, some it can't. Check the options.