Sudden temp rise at idle

Question

i reseated my heatsink today cause i took the mobo out to see if a mod idea would work.  i put it back on same as i've always done except now my cpu temp is almost 10 degrees hotter.  it's around 62-63C idle and i think that's much too hot.  you can see in my sig what it used to be.  any ideas on what might be causing this sudden rise?  even with the case open the temp remains high.  
believe it or not my chassis temp is actually lower by about 2-3C.  i did move a fan so that might be causing the chassis temp drop but i don't think it would cause a ten degree drop even with the case open.

Answer 1

there has been one chip since forever but there are newer ones.  with my old hsf i put it on wrong once so it may have caused a small chip and then with the amount of pressure it takes to put my volcano 9 on it may have grown a bit.  the chips i am talking about are very small.  one corner that has always been chipped is about the size of a pin head.  the longer chip that has grown a bit is along the opposite edge starting at the corner and travelling about 4mm along the edge.  and it's only about 1 mm deep.
for now i have it unoverclocked and it's running at 56C idle which is still much higher than the 49C idle it used to be when unoverclocked.  i will try reseating again in the morning.  it's a pain to do cause the way my power supply is situated i have to take the whole mobo out which means disconnecting everything.
i just checked my vid card temp and oddly enough it's at like 48-49C idle when it used to be at 42C idle and 46C full load.  since i unoverclocked, my chassis temp has dropped 3C.  do you know where the temp gauge is for the "chassis"?  don't think the vid card temp is related but it's just odd that all my temps are acting kooky.