Good job on the 4.5ghz but like everyone else has been saying, put the vCore down! Wayy to high.. I've got my E8200 running at 3.8ghz at 1.25v. I was scared to put it at 1.35.
Also, even though you've managed to run the system at 4.5ghz, it may be the case that the chip will never be stable at that speed regardless of what settings you have in your bios.