I'm running Linux v0.94Beta, installed from the .deb downloaded from SF, on Xubuntu 14.04 "Trusty". The icon doesn't appear in the System Tray, rather it appears in the center of the desktop. The icon functions normally if you double click on it, but it's in the wrong place.
Not sure if this is the product of some abnormal interaction between pwsafe and XFCE. I may try this on some other distro, in a VM, to see if the behavior persists.