http://www.freebsd.org/releases/8.1R/errata.html


A deadlock can occur in UFS with the QUOTA enabled due to a lock order
reversal. This problem has been fixed in r209367 (HEAD). An Errata Notice for
8.1-RELEASE is planned.

A legacy device detection in the ata(4) can fail in some cases. Specifically,
Marvell 88SX6141 controllers can cause attach failure or panic. This problem
has been fixed in r210168 (HEAD). An Errata Notice for 8.1-RELEASE is planned.