I have TwonkyVision 4.2Q running on my nas (QNAP TS-101)
and can play audio/foto/video on my laptop running Nevo
Media Player 2.0
I have not found any mp3 not working. But all my mp3 tags
are correct. But before adding any audio files to my collection
i always update the tags.

But if Nevo Server can not use the files then switching
to a different server does not make mutch difference.
The same file will be streamed from Twonky to Nevo Player.
Nevo Player has the same file type support as Nevo Server
and the problem of the file stil exists only on a different
place. Twonky wil not change the file.
Try fixing the files (tags) in the way Nevo Server can
use them then Twonky and Nevo Player combination will
work also.