The 2005 clears this up and it is allowed. It was never really the intent that NM was not allowed in raceways, but I won't dwell there.

Article 362.22 (all the xxx.22 sections are the same)

Cables shall be permitted to be installed where such use is not prohibited by the respective cable articles. The number of cables shall not exceed the allowable percentage fill specified in Table 1, Chapter 9.

Roger