Disabling a udev rule that calls part of libata and does some other magic seems to prevent the HSM Violation. This is a temporary workaround until the kernel bug is resolved. Infohere.

For the record, this is on an Acer Aspire One ZG5 with a SuperTalent FEM32GF13M 32GB SSD running Debian/Squeeze and 2.6.30-2-686.