I installed 0.3.1 on my iBook PowerPC 750 with OS 10.3.5 installed. Per the suggestion below, I repaired the permissions. Although the tiny telephone icon appeared in the menu bar when the application was opened, there was no change in the icon when the fax was being received nor when the transmission of the fax had been completed.

I had previously installed version 0.3 and had obtained the same results.