With UltraVNC 1.0.8.2 is installed to Windows XP (full install) and running as an application.
If you use WINVNC.EXE 1.0.9.6 (placed in another folder) and make it connect using "WINVNC -connect hostname", it does nothing. In previous versions, it signaled the UVNC 1.0.8.2 that was already running to connect.