Re: Unable to load nvidia module on FreeBSD 8: link_elf: symbol linux_ioctl_unregiste
i had the same issue at some point. for me removing /usr/src completely and getting a fresh snapshot of it solved the problem though.
i don't think the problem is within the nvidia driver, because i also experienced problems with other 3rd party kernel modules at that point (virtualbox e.g.).
i posted my problem in september 2009 on the freebsd-current@ mailinglist (topic was "problems with r197427 (i386) and nvidia driver ").