Re: FreeBSD problem
Your problem probably has to do something with interrupt latency. It seems your kernel has had some major interrupt latency surgery, and that might just have bitten your Nvidia driver. Hopefully someone else comes up with a better idea of what's wrong, maybe googling along the lines of "interrupt latency freebsd nvidia" will point you to a solution.
(If you're really stuck, post the relevant parts of the kernel log, X log, X configuration and the output of lspci -vv.)