No, still not an issue, even at idle. People amaze me - they always freak out when they see temps over 60C on integrated circuits. Yes, the hotter they get, the more likely there's a chance of failure, but if you take apart a modern GPU and look at the heatsink, it's easily 1/4 to 1/2 the size of what people consider "normal" for a modern CPU heatsink. The fact that companies like nVidia and AMD/ATI can engineer a chip that operates NORMALLY at temps that range from 60-90C should be amazing to most folks, given how much they freak out about it. Intel makes CPUs (i7's, i5's, Core 2 Duos) that can easily handle 100C if they need to.
But if you have an OEM video card, and haven't modded the heatsink, and you're getting 64C idle, you have absolutely nothing to worry about. I wouldn't even worry if the idle temp was 70C. If the load temp stays south of 90C, it's perfectly fine, and if the card is operating without any visual artifacting, that's another hint that the card is fine.
