1999 Honda Accord Steering Wheel vibration

I have small vibration in the wheel when I drive first thing in the morning by the time it warms up (about 5 min). I had upper engine mount replaced, but it's still there. The bigger problem is that couple of times while driving at about 65 mph I get this weird vibrating noise coming from the front, and I was hoping this is due to the engine mount, but it still there. My mechanic tells me it could be ABS or trasmission gets stuck in this overdrive mode. The problem appear as if I go around 60mph, or higher then I lower the speed, then suddenly want to go faster. Last time when this happened, I tried to go even faster, but I think car was more resisting then when vibration was there. Then I tried to apply brakes, and vibration was even worse. My mechanic tells me that one rotor is a little warped and one tires makes a little noise, but I just wonder if warpped rotor or tire could produce this much noise. I still think problem is more serious, like transmission, or maybe even this ABS. Also, I bought this car used with 103K miles on it, and front tires seem to be pretty new. When in normal condition, there is no vibration or anything in the wheel. Thanks.