Heh, Ok, PCBSD runs on FreeBSD which uses a different file system,
UFS2. To mount it from Linux you have to make some adjustments to the kernel. This is is the second time this question has come up, I'll add it to the FAQ by the end of the week, I think.
As for reiser, there is no read support in the default install--there may be some in the future, as FreeBSD-6 (which is now CURRENT and not for production) is planning, I believe, to add it to the base system.