Speedo not working transmission not shifting?

I've had issue with the the speedometer needle bouncing all over the place every occasionally when driving and then just recently once in a while it seems like it doesn't want to shift from 1 to 2. It doesn't shift until the RPMs get up to around 2200-2300. Someone told me that their car was doing the same and it was a faulty speed sensor. I googled it and the symptoms were the same. Had a diagnostic scan done at auto zone and it came back with that code as well as a leaky vaccuum hose (I think) but I was told that code that was given for that was not the right code and didnt make any sense because if that were the case I'd have no brakes. They thought it was just triggered by the speed sensor. I had the sensor replaced and it seemed fine for about a day then started in with the same issues. Took it back and had the throttle sensor replaced and the scan done and there were no codes. Got it back drove it home, drove it later that night and the same issue. I'm supposed to take it back in tomorrow so they can take another crack at it but thought I would see if anyone has had issues with this or if you have any suggestions? Also just had new brakes on front and back replaced and my abs and brake lights are both on.