If it doesn't pan at all, I'd first check the Mixer window in PT to see if the MONO mix option is enabled. I think it's on the bottom of the mixer.

After that I'd check the audio options in Windows.
Since W7 the 1010 mixer is also controlled in the Windows mixer section.

Right-clicking the speaker icon in the lower right taskbar can reveal the Windows related options (Windows playback devices and recording devices etc.).
Quote:
Say a hi hats at L and a ride cymbal at R. Now when I try to pan the whole track to the L or R of the sound stage as I listen through headphones or through my amp and speakers, I just hear either the L side content , or both, or the R side content. But I cannot move the content as a whole to the L or R of the sound stage as I used to be able to do! Very frustrating when you're trying to construct a song as a whole with a clearly defined location for each source, eg. vox, keys, bass, gtr etc!


This is something I've had a lot of trouble explaining/expressing.
It is better to record everything as a MONO track, and use 2 separate MONO tracks to record a stereo signal.

Why?
Because then you have better control.
If you use a stereo track, in order to move something to the left you lose some right, and vice-versa.

If they are 2 MONO tracks you can make a stereo piano still have some 'space' (L/R) but be towards the right side of the sound stage.
Ex: Panning one side of a stereo track -80 and the other side of the track -40 (by using 2 MONO tracks) still gives it some space, yet retains direction and place.

Your 1010 will record either 8 MONO tracks or 4 stereo tracks.
I ALWAYS prefer the 8 MONO tracks. In RB/PT this is determined by the Track Type you are recording to.
If the armed track is a MONO audio track, the program will record the rest of the tracks as MONO and insert them on the next available blank track(s) as MONO tracks.

If the armed track is a Stereo track, you'll end up with 4 stereo tracks instead.

Like I said I much prefer 8 MONO tracks, as I may be recording 8 separate audio inputs, and have the bass on 7 and guitar on 8 .. I want total control over each of them as individual tracks, and not have to lower the bass to increase the guitar (like a stereo track would), or pan them in a restricted way.

Check if your default track type changed to stereo. If so, make sure the track you arm is MONO (and change the default setting in Options if you can). Then later you'll have all your panning options available for mixing.

Make your sound your own!
.. I do not work here, but the benefits are still awesome