Vibrates on Acceleration

My 2001 Mazda Millenia will vibrate on acceleration, it is worse between about 60-70, and especially uphills, we have had a complete tuneup on it and they replaced plug wires and all of that, we have also got 4 new tires all the way around and that didn't help, we have changed the fuel filter, and we have checked the motor mounts and they are not loose, anybody think they may know what could be going on here? One of the mechanics thought that it could be the struts but didn't really know, we don't want to spend the money on new struts of it doesn't need it. Thanks.

have you had any tranny work on this?

No, it shifts in and out of all gears fine, when it does it I have shifted into a different gear and it does it just the same.

How many miles are on it? Waht kinda condition are the front axles in?