I'm having an odd problem.

I'm playing Oblivion on a laptop, and want to limit the framerate to 30 to prevent the thing from getting too hot/noisy. But I've discovered that Oblivion completely ignores framerate caps.

This includes ones set through ENBoost, Oblivion Stutter Remover and OBGE/Oblivion Reloaded, as well as Vsync forced through the Nvidia drivers (other stuff set there, like anti-aliasing or anisotropic filtering, seems to work fine).
Enabling Vsync in the Oblivion launcher caps the game at 60fps like you'd expect.

Has anyone experienced this before? At first I figured it was just some weirdness between OBSE and the GOG version, but since it also ignores ENBoost and the driver settings that can't be the case.

EDIT: I played around some with Nvidia Inspector, and while setting Vsync to 1/2 screen refresh rate (as I usually do to get a 30fps lock) does nothing, the Frame Rate Limiter works! So that solves my problem, though I'd still like to know what is going on...