Line up the valve stem as TrojanHorse recommends, note which side is facing which way on the wheel. Next flat find the leak and then compare its location to the tire and rim to find the cause. Are you using levers to mount the tire? If so stop doing that. You could be pinching the tube between the bead and the rim, to fix that only put 10psi in the tire then pinch the tire back from the rim all the way aroung the tire both sides to make sure the tube is not pinched, only then inflate to ride pressure.
I do not agree that the problem is either high pressure or too narrow of a tire. However if you want to improve your ride quality consider switching to 25 or 28 mm tires. The Spesh Roubaix 23/25 are rather nice tires. I like them.
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Sir Mark, Knight of Sufferlandria