AGP bus and PC bus problem

My specs are below. I now run at 9.5x133. In sissoft sandra. It's is saying that my AGP bus is at 89mhz?!?!?!?! I sured speeded up my FPS in games. Like by 20. But the video would crash after 1/2 hour of use. I posted in video and cooling section, and someone told me that my AGP bus should be half of my fsb. Which would be around 66. But this isn't the case. I have a 266fsb Tbird, and to reach this, I needed to set the fsb on the mobo to 133. Can someone explain to me what is going on?

Actually, AGP buses generally are set to run at 2/3 FSB, so 89 MHz doesn't sound odd, except for the fact that boards that do officially accept 133/266 FSB should change the PCI and AGP dividers to 1/4 and 1/2 FSB, respectively. So, if 133/266 FSB is a "standard" setting for your particular mobo's FSB, then I think your AGP should be 1/2 that (133), or 66MHz.

I also think I heard somewhere that some boards don't necessarily use 133 as a definite cutoff point for the divider change. So maybe something like 135 will change the div? I dunno, it's just a thought.