For some reason, this affects my desktop, but not my XP VM.
Specifically, on the XP VM, the pid file is left behind. But it does not cause PyHoca-GUI to display the message. (Nor does it prevent PyHoca-GUI from launching pulseaudio.exe.)
Desktop (executor): Windows 8.1 64-bit with update 1 Multiple sound adapters. Adapter listed below is the current default: Audio driver name: SB Recon3D PCIe Audio driver provider: CREATIVE Audio driver date: 7/30/2013 Audio driver version: 6.0.101.57 Audio driver installer: SBRP_CD_LD_1_01_26.exe Audio driver date (according to website): 29 Jan 14 Accessed locally
XP VM (mothership-xp): Windows XP 32-bit SP3 Running on Fedora 20 kvm/libvirt kvm/libvirt set to provide "ac97" audio Audio driver name: Intel(r) 82801AA AC'97 Audio Controller Audio driver provider: Microsoft Audio driver date: 7/1/2001 Driver Version: 5.1.2535.0 Accessed over SPICE with Virt-Viewer 0.6.0 64-bit from said desktop.