From the OP the first thing that comes to mind is the Abit board. Abit was a fantastic overclocking board manufacturer, but my anecdotal evidence is that they were not very stable boards at default levels (or at any level). They just were better at overclocking and when running at increased bus speeds they were more stable than the competition at the same speeds.
The AMD platform at the time split between 2-4 different chip-set providers also lead to issues. None of the platforms were that great. ATI feature limited. Nvidia great performers and nice features had several annoying bugs. VIA was a mess with driver issues, features wavered back and forth and probably the most unstable. Ali their last hurrah was fine, but performance was way down and features again severely limited.
AMD buying ATI was great just on a chip-set level. And is pretty bullet proof by this point.
But anyone running a Apollo Pro133A based board or even a Nvidia NForce board on the Intel side will run into the same issue. Back when Toms-hardware did an up-time comparison of a P4 Extreme edition and a FX chip. They choose an NForce board so they could both have an SLI setup in them. They were so surprised when they had nothing but issues with the Intel system and had to eventually dump the board, chipset, and a vid card. It's that test that stopped me from reading their site anymore.