Part of the issue is that there is no such thing as a WMA file. A WMA file is a container... You may have OGG encoded files, or some other codec that itunes doesn't understand there...
Yes iTunes maybe able to play the file, but if the iPod doesn't natively recognize the audio format/codec, it won't be able to play it. iTunes is programmed to detect what the ipod can and can't play...
What codec's are the files in question?
Try converting through iTunes, because WMA doesn't appear to be supported... Evidently the WMA support I've read about is due to being converted through itunes...
iPod can play songs encoded with these codecs:
- MP3 (from 32 Kbps to 320 Kbps)
- MP3 Variable Bit Rate (VBR)
- AIFF *
- WAV (with no compression)
The following require iPod software 1.3 or later:
- M4A AAC [*]
- M4P AAC (Protected) [*]
- M4B AAC (iTunes Store Spoken Word files) [*]
The following require iPod software 2.2 or later or iPod mini 1.1 or later:
[*]Requires iTunes 4 or iTunes 4 for Windows. AAC files also require the most
recent update to the iPod software.
Compatible sample rates
iPod can play songs with the these sample rates, and with all compatible codecs:
- 8 kHz
- 11.025 kHz
- 16 kHz
- 22.050 kHz
- 32 kHz
- 44.1 kHz
Audible Spoken Word files
iPod Software 1.2 and later can play Audible spoken word files in formats 2,
3, and 4. These files have the filename extension, ".aa".
iTunes 4 and iTunes 4 for Windows work with Audible spoken word files.
iPod cannot play songs that use these audio formats:
- WAV with compression
- WMA and WMA Protected
- any other format not in the Compatible codecs list