Doors and Windows - Why hairline cracks above and below door hinges?

I repainted my door frame, put new hinges on, drilled pilot holes for the hinges, but I am getting a hairline crack in the door frame 1.5" long above the screw hole on the top and below the screw hole on bottom of the hinge?? The house is 30 yrs old these may have been there? They are tiny but can be seen on the new white paint. What can I do? Just paint over them until they are filled?

It happens, the holes might have needed to be 1 size bigger, or some wax or soap on the screws may have helped. You don't have as much wood trying to hold the fibers together at the top and bottom.

Don't sweat it too much. Put some caulk into the cracks with your finger (well, you could even use glue if ya want) force it in real good, then lightly sand w/fine grit and touch it up with paint.

Might want to wait until the heating season and see how it looks as the wood drys out. Better to fill and paint when the crack is the largest.

Thanks!! The cracks were already in the wood behind the hinges. The builder did not drill the hole for the hinges in strait so I glued dowels in and redrilled using a Vix-Bit. The drill bit was the same size of the body of the screws so only the threads were larger. It seems the small crack starts to split when I get the screw 98% of the way in? Weird? Anyway I just used shorter screws and it did not start to split? I will just paint over it now to fill the tiny crack, I mean it smaller than than a piece of hair. I just don't know what else I could have done? Drilling one size up was just about the same diameter as the OD of the threads on the screws, that would not have been a good either.