Me too.
GF4-4200 128 meg
512 meg system ram
athlonXP 1700mhz.
It even happens when I'm just flying along, nobody really all that close to me. I was taking a goon to and from a V base at very low altitude and every couple of minutes the screen would freeze and I'd almost run into the ground or trees. No enemies were around, but there were a few friendlies, mostly outside icon range though.
I haven't pinned down exactly when/why they happen since I was getting them both while dogfighting and on my goon runs with nobody very close to me at all.
Maybe the textures or whatever is causing the pauses could be trickled into memory, interleaved with other stuff, instead of dumped in all at once?