TiLP won't work with a CAS+.
You need an old TI-Nspire Computer Link Version: 1.0.59http://tiplanet.org/forum/archives_voir.php?id=1439
It has an update menu, but it's totally useless as no CAS+ OS has ever been released publicly by TI, and no CAS+ ROM has ever been dumped up to now.
You won't be able to update and have to stay with that awfull 1.0 OS.
Hope it wasn't expensive...