As far as i know Virtual H Shift emulates virtual joystick. Unfortunately I haven't seen x64 drivers for it but I may be wrong. For example I'm using PPJoy (it has unsigned drivers) software on my PC (with Vista SP2) and to run my little prog(it's emulate wheel) which use Virtual PPJoy drivers I have to switch my system to test mode. To do that you need to open CMD and put there BCDEDIT -SET TESTSIGNING ON and restart.
Than reinstall H shifter. Maybe that could work.