Losing song id data when running noise reduction

[gopitsch]

Using mp3 file created using Music Match Jukebox and running them thru the WavePad "Noise Reduction - Apply Auto Special" @30% I lose the album name, track no., and genre identifications and the artist and title is combined under artist on roughly 35-45% of the files subject to the reduction. The other 55-65% retain all their file identification info just fine. The files are mp3 and 128 kbps going in and being saved. I am using Windows XP if that matters. I would greatly appreciate any help solving this. Thanks in advance.