The ASUS A7A266 is a fairly stable chipset, although the performance of the board with SDR RAM is fairly poor, and in many cases the A7V133 will probably outperform the A7A266.
Currently there are a few strange quirks with the A7A266 as well, such as onboard audio not working properly (if you use it), problems with running 2 DDR DIMMs at 266MHz, some board revisions do not have multiplier adjustment....although you can mod the board if you wanted it.