Strange vibration at really high AND really low speeds: 1999 Camry LE

[gammasphere]

I have a 1999 Camry LE. I bought it used at 95,000 miles. I recently got the timing belt replaced, transmission fluid flushed, and an oil and filter change.

All of a sudden, the car has been vibrating at really high and low rpms (vibrating more than it was before and more than I think is usual). This never happened before, and what is stranger, is that in the morning when I drive to work in 20 degree weather, there is no vibration!
The car only vibrates on the drive back home when I go beyond 2,700 rpms and lower than 1,200 rpms (I drive 60 miles one way to work and I don't drive over 80 mph). When I am in between those two marks, the car is as smooth as butter.

Could this be caused by any of the changes I mentioned above, like the timing belt replacement or the oil change and the transmission fluid flush? Also, my drive consists of 15 miles of traffic driving, 30 miles of 55-60 mph driving, and 15 miles of highway.

I really need some help, because I am worried about my car!!!

[It is a car!]

I am no expert on the subject but I think you should double check
the trans fulid level.

[Neinta]

Also check your tires. My mom's toyo van vibrated at low and high speeds (but not in between) and it was because of uneven wear on the tires.