I have taken a quick look at the Mr Chips site but cannot find the mobo you quote. There are quite a few M810 models and it loks as if these are all MicroATX. From what I can see, there is no reason why your current mobo should not support the Duron 1.8 Mhz. If this is fairly new, I suggest you take it back and see what's gone wrong. Alternatively, I would have thought you could still buy an identical replacement. If not, then almost any mobo which supports AMD should provide all you require, although, having gone for a MicroATX previously, perhaps you should stick to this reather than risk the full ATX models.