Maybe your E115G came with the optional non-working sound with snails support.
I've tried it on my E115 and it seems to work fine with the sound.
Try removing it through the Remove Programs in the control panel. then re-install the latest demo through active sync into the main memory. This should clean out any snails residue (yucky, slimy stuff) left on your PPC and replace it with a fresh one.
If that still doesn't work, maybe your E-115G really doesn't support sound in Snails.
