What's room temperature?
I find on my custom loop that my idle temps are typically about 10°C above room temperature, on a hot day my chip will idle at 45°C despite the ridiculous cooling I have on it. Hence the disadvantage of relying on ambient air to cool your components.
My old 212 EVO (which is roughly equivalent to the H60 in performance) was about 15°C above room temp. So if room temp is about 25-30°C then I'm not surprised your idling at about 42°C.
well, something is wrong with your setup maybe. I use Arctic Silver 5 thermal paste with a stock intel heatsink. My ventilation is awful as i dont have any case fans attached, the pc case is really crappy(Only some small holes for ventilation in the back panel) and the operating room temp is about 29C. Though my cpu idle temp is about 34C...