I can confirm this bug. Updating from 2.6.20-15 to 2.6.20-16 breaks luks/dmcrypt. I my test setup I used a partition that gets decrypted while booting ("Starting early crypto disks"). With 2.6.20-16 the kernel does not recognize the partition and drops with errors into single user mode.
If I remember correctly when installing the crypto stuff a new personal initrd.img-2.6.20-15-generic was created for supporting the crypto stuff, probably this step is missing when updating the kernel. This should definitely be done automatically.
I can confirm this bug. Updating from 2.6.20-15 to 2.6.20-16 breaks luks/dmcrypt. I my test setup I used a partition that gets decrypted while booting ("Starting early crypto disks"). With 2.6.20-16 the kernel does not recognize the partition and drops with errors into single user mode.
If I remember correctly when installing the crypto stuff a new personal initrd. img-2.6. 20-15-generic was created for supporting the crypto stuff, probably this step is missing when updating the kernel. This should definitely be done automatically.