The Lynnfields do run a bit hot, but you shouldn't be seeing temps like that, even with the stock cooler. Temps above 72 celsius aren't safe for long term usage. You may need to reapply the thermal paste. It is also possible that the plastic frame of the stock cooler has warped, and the cooler is no longer making proper contact with the CPU. That has been known to happen over time with Intel's stock cooler.
It might be a good time to pick up an aftermarket cooler. I personally found that the stock cooler wasn't that great on my i5 760, only barely keeping my load temps below 72 celsius, and only when the ambient temperature was around 20 celsius, not great for summer operation.
Thanks, then I'll get a new cooler asap. I'm looking at CM Hyper 212 EVO.