It looks like Steinberg adopted this optional format for CD-ROMs which includes this JUNK chunk in the header . I checked some of my older wave files from Cubase 4 and it did not have it.
To align RIFF chunks to certain boundaries (i.e. 2048bytes for CD-ROMs) the RIFF specification includes a JUNK chunk. Its contents are to be skipped when reading. When writing RIFFs, JUNK chunks should not have odd number as Size.
http://www.sonicspot.com/guide/wavefiles.html
http://www.daubnet.com/en/file-format-riff
Does anyone know if there is a setting where I can turn this off?