Comment 68 for bug 509180

While it doesn't seem to be the focus of this bug, the relevant bugs have been marked as duplicates of this one.

I'm running 2.6.38-8 in Natty beta, and still getting a lot of

Apr 12 14:46:32 puppy-ubuntu kernel: [31106.234038] Valid eCryptfs headers not found in file header region or xattr region
Apr 12 14:46:32 puppy-ubuntu kernel: [31106.234047] Either the lower file is not in a valid eCryptfs format, or the key could not be retrieved. Plaintext passthrough mode is not enabled; returning -EIO

so it would seem that either the patch hasn't fixed this, or #372014 is not actually a duplicate.