"Every X seconds" is not affected by the framerate - it runs based on real-world time rather than ticks.
However, I think a few people are being thrown off by a current bug in Chrome 18. If there is nothing changing on the screen, the game will start running at hundreds of frames per second and the timers all screw up. The fix is to make sure you change something every frame - try just putting an unused text object outside the layout and always set it to tickcount to fix it.
The problem should not happen in any other browser and is also fixed already in Chrome 19 so should disappear in a few weeks.