No sound on China2Go on Palm Zire 72

Loaded both prc and pdb files onto Palm Zire72 running Palm OS 5.2.8. Successfully activated program and registered with license key. No sound at all when tap speaker icon. My sound from other programs on Palm is working fine,like Real Player. Loaded programs onto main memory. Main memory has 7mb left after loading. De-install all China2Go programs and reloaded again. Still no sound. Please advise. Thinking buying dictionary also. Anxiously wait for support.