The oil pooling is a legitimate problem and the fix that MACDRIVE posted will fix it, however, if the bolts are leaking oil up the threads it is most likely that the vehicle has enough miles on it that the LIM gaskets should be replaced BEFORE they spring a big leak. Think of the oil pooling as an early warning sign for the LIM gaskets failing. Any time the LIM bolts are removed, the threads should be coated with a sealer. GM recommends Threadlocker 272 GM P/N 12345493 (Canadian P/N 1095348
Why they leak is up for debate, I don't know myself for sure, but I would venture to guess that it may be caused (or progressed) by a faulty PCV valve. You see, there is no oil PRESSURE behind those bolts so you can't attribute it to oil pump pressure. The back side of those bolts are in the crankcase (zero pressure) side of the oiling system. It is the PCV valves job to make a slight vacuum on this side of the oiling system to prevent such leaks/seeps and to scavenge combustion gasses from the crankcase.
If the PCV valve fails or lacks performance, than combustion gases will build in the crankcase and produce a positive pressure. That pressure needs some place to go and it will find the easiest way out. That way out may be a seal, a gasket or a bolt thread. Which ever is the easiest way (least resistant...weakest sealing point).