Dir command works like a charm but i stil cannot play any of the wav files (made them with audacity).
Have you tried just typing: play font01/hum.wav or similar?
You didn't save the wav files in a compressed or floating-point format I hope, because teensysaber only supports
PCM files. The playback speed must be 11025, 22050 or 44100Hz, and it should preferably have 16 bits per sample.
About SDcard... I've tried two 1gb microSD cards, which performs great with my mobile phone, USB reader, etc. I formated them in FAT16 format with SDformatter. I tried even two microSD card readers but the same problem persist. I used AWG26 wires for connecting SDcard adapter. Lenght is about 90mm. As a electrician, my soldering skills are pretty good too.
90mm may be too long. But maybe not since you can list files.
(At a few Mhz, the capacitance of even fairly short wires can become a problem.)
If you get hangs while playing sounds, try making the wires shorter.
I tried to use the serialflash method but honestly don't know how to upload the files onto chip :S
Easiest way is to use MTP, at least if you're on windows.
You just need to compile teensysaber with the usb type set to MTP.
If you're on a mac, you'll need to install MTP support, which I think comes from the android SDK.