Add some more ventilation/cooling. 60C idle is WAY too much.
Nope, for the GTX260, 60'C idle is totally normal. They have relatively low fan speeds and generally idles at around 60'C and goes up to 80s'C at full load.
The 65nm idles around 60'C while the 55nm version generally idles around the mid 50s'C. My 65nm GTX260 sp216 idled at around 59'C with 40% fan speed at idle.