Burn wav file with nero: problem

hi

i 've just started recording own music using cubase sx. after mixdown of a song, the exported .wav file is 243 MB. In nero (version 6.0.0.0), i choose compilation of music cd, but when i drag and drop the specific file into the compilation, there is a message saying “some files could not be added” and the file cannot be added to the list. any idea what’s wrong? is the file too large? or could there be sth wrong during the export of the file?