we are the local agents for MSI so i get them (and pc components in general) for practically free,
i upgrade my pc an average of once every 3/4 months (with a new mobo most times)
ALL were MSI, i have NEVER had even 1 failure - some minor issues which were corrected with bios updates but no board (same thing with the VGA cards) EVER failed on me. I've been with MSI since the P3/ Athlon days so i've been through pretty much almsot every board in their product line.
so tbh the chances with all due respect to you, are that you are ham fisted (ie hard on your components) or have some electrical problem - either powersupply or at home.
best regards
Kurt
Edit, oops i got wrapped up in the msi issue,
regarding the northbridge issue, since its a small high rpm fan (especially if you have an intake fan facing it on your side panel/window) it is very prone to failure from dust. This will happen again (with varying time periods) to any fan you'll but there. IF you arent overclocking my reccomendation would be to go for the zalman NB47 heatsink, its effective, and its passive so it will last for ever

If you are overclocking the thermalright nb cooler and the vantec iceberg are both excellent alternatives - but in this case double check for dust inside the case. If you have then invest in some filters - your pc in general will last you longer and you will get much more effective cooling (dirty heatsinks are less effective)