Statutory Habeas is unavailable where an intial challenge to the conviction was made in the court of conviction according to statute, but there was a subsequent change in the law regarding the predicate offense that cannot be relitigated under AEDPA, since it would be second or successive. The inital collateral challenge was adequate and effective.
https://www.ca10.uscourts.gov/sites/ca10/files/opinions/010110561337.pdf