I got exactly the same problem! first it didn't work and then after adding corecrypto.kext to my /extra/extensions folder it worked.
I installed from 10.8.0 with Sinetek's original kernel. Then updated to 10.8.2. Anything that I have seen since just instantly reboots after processing kexts.
After processing kexts, it loaded this corecrypto and it booted.
But now it looks like it can't boot the corecrypto anymore ;0
Anybody who nows how to be sure it boots this kext?