phone does not see all songs

Phone does not see all songs on the card.  Have transfered songs (m4a format) thru Media Manager and thru Explorer. Reformatted the card.  Both Explorer and Media Manager see the songs on the card, but the phone only sees a few of them (tried multiple card refreshes).  Click the songs via Explorer or while connected to Media Manager and they play just fine.  Phone plays the few songs it sees just fine. Tried with 2 different computers too.  Driving me nuts.  Any tips??

convert them to Mp3, and Delete the piece of junk Sprint Media Manager.  You are probably going to have to format your SD card now, that Sprint Media Manager has gotten ahold of it.  Yes sad but true, sprints software sabatoges its own phone.   After you have formatted your card, just plug the phone into your laptop, and click on start, Computer (my computer on xp) and in the list of drives you will see a removable drive.  click on that and go to the music folder.  Just drag and drop, or cut and paste, which ever makes ya feel more giddy!

I had a similar issue.  I used Sprint's Media Manager to xfer songs and for some reason it didn't recognize the tags (artist, album, album art, etc) for some of them.  I was able to see them under 'All songs' tho.