I have the same problem. The service crashes during install.
Error message detail:
Tunneling proxy crash:
Problem Event Name: APPCRASH
Application Name: 3CXTunnel.exe
Application Version: 6.0.3545.0
Application Timestamp: 49130281
Fault Module Name: LIBEAY32.dll
Fault Module Version: 6.0.6001.18000
Fault Module Timestamp: 4791a7a6
Exception Code: c0000135
Exception Offset: 00009cac
OS Version: 6.0.6001.2.1.0.256.6
Locale ID: 4108
Additional Information 1: 9d13
Additional Information 2: 1abee00edb3fc1158f9ad6f44f0f6be8
Additional Information 3: 9d13
Additional Information 4: 1abee00edb3fc1158f9ad6f44f0f6be8
I tried to install it using the command line, same result.
I'm running Windows Vista Business, all patches installed to date.
Help would be greatly appreciated