Re: FreeBSD: IRQ sharing?
That's a interesting problem you have there. I have similar config (except that I run -CURRENT and not release, and don't have nForce board), but 5.2.1 should not have problems with IRQ sharing. (I've used my setup with 5.2.1 too without any problems in console)
My guess would be some issues with the system drivers with the network driver vs. he gfx driver, since they are both nVidia. Might be worth posting to the current mailing list, or creating a PR (or if you dare and don't mind living on edge, updating to current).
But I must warn you, you won't be able to run X with that card, as the NVidia driver (at least the freebsd one, I've tried linux too, but not sure which version it was) does not support the 5700 chipsets (although the readme claims that it does - I've emailed Nvidia about this, no response yet [it's been 2 weeks]).
Looking at the driver, it knows the card is by nVidia, but has no idea about the card chipset.