Comment 1 for bug 388556

It looks to me like the XVoiceFax application needs to be updated. The error message from Process.vala that is being shown happens after AllTray attempts to find an application the normal way, that fails, and then it tries really hard to find a window that matches the spawned process.

This requires that the target application (either directly, or through use of its toolkit) comply with current standards (namely, the ICCCM and the EWMH). Partial compliance may also work; try just setting _NET_WM_PID on the windows that the application generates to see if that fixes it (at least with AllTray).

I'll fix AllTray to better report this error condition. Thanks for the report!