I'm pretty sure you've got your numbers almost correct...
AGP and PCI both run at a multiple of the system bus. The BX standard allows PCI multipliers of 1/3 and 1/2 and AGP multipliers of 1/1 and 2/3. Modifications to BX allow for a 1/4 PCI multiplier and a 1/2 AGP multiplier (for 133Mhz FSB, all 133Mhz chipsets will have these multipliers...e.g. i8xx)
Both PCI and AGP devices must run at a *minimum* of 33 and 66Mhz respectively. So you use the multiplier that will give you a value closest to the desired frequency without going under.
I have a Celeron 400Mhz running at 500Mhz. In order to do this I had to increase the system bus speed from 66Mhz to 83Mhz. My BE6 only has AGP multipliers of 1/1 and 2/3 so I chose 1/1 which means that my video card is clocking at 83Mhz. I chose a 1/2 PCI multiplier which means that all of my PCI devices are clocking at 41Mhz.
You know, I just reread your post and you mentioned you were running an 800EB. Technically you're not overclocking your processor, and if
the BE6 II has real 133Mhz support, you're not overclocking anything. Let's see here..............damn i have to download the entire manual to find out...........nope, I guess you are running your AGP at 133 * 2/3 = 89Mhz...yipes!
Now, these are external bus speeds. The core and memory speeds on your video card are completely independent (for the most part) of these speeds. The core speed is the speed of the card's processor and the memory speed is the speed that the card's processor talks to memory. So adjusting these values *probably* won't make much of a difference. Even if they do, they're not making a difference in the way you're thinking, and I still wouldn't call your system stable.
My first recommendation is to trade the 800EB in for a regular 800. I haven't seen enough evidence to demonstrate that the extra 33Mhz bus speed offers much performance increase on the BX chipset.
My second recommendation is to trade the BE6-II in for a new motherboard that supports 133Mhz FSB (for real). The BE6 is a great board but it's for *real* overclockers. You're not really intending to overclock, you just happen to have an EB processor.
My third recommendation would be to trade the video card in for something that will be more stable. This one I'm not too keen on because while at first I thought you were intending to overclock, it sounds now like you're just looking for a stable system. Running AGP at 89Mhz might be something that a geek like myself might be ok screwing around with...but if you're not into it, don't do it! I have never in my life seen a video card go bad....and I've always overclocked. The fact that you blew a V3, one of the more stable overclockers, suggests that maybe this setup isn't right for you.
Whatever you decide to do, no amount of tweeking is appropriate. Setting your monitor to 60Hz surely isn't a good solution to this problem. It would drive me nuts!
For the most part it sounds like you got a system with some decent components...which is rare for a machine that comes from a shop. If it weren't for that EB processor, you'd be golden.
Good luck to you!
Slackmaster 2000