I had a similar problem with that particular version of LaunchELF (I have the same setup as you, Infinity & LaunchELF configured to triangle). For me HDLoader worked for a while and then suddenly stopped; as did PS2Menu and any program that used the cdvd.irx module. To solve this, I had to drop back to an earlier version of LaunchELF. Everything has worked perfectly since.
I know it's not the exact same problem an you, but give it a try. I hope it works.
Silver PAL V10, Matrix Infinity, Romeo Mod, 120Gig HD