[napolienne]

1) Check the tiller again now your limbs aren't so hot. Is it still 0mm?

2) If it is and your limb bolts haven't moved, check the dovetail fittings in the limbs. Does the sprung bit travel smoothly if you push it, and does it travel the same amount on both limbs? Are there any signs of stress on the limbs? Do they both have the same profile if you hold them next to each other?

3) If the limbs and limb fittings seem fine, adjust your bolts so that the tiller is back to what it should be. Check your tiller every time you set up, halfway through, and at the end of each of your next few shooting sessions. Write down the measurements. Is the tiller changing?

4) If it is changing, put your limbs in your riser upside down. Is the difference between the two the same but inverted? EG where the bottom limb was previously Xmm less than the bottom, is the top limb in the bottom pocket now Xmm more?

5) If no - the difference is the same but NOT inverted - the most likely cause of the change is your bolts.
If yes - check the limbs in someone elses riser - is the tiller difference significantly more than they would expect?

If yes to that last one, you have precisely what has happened to me with my last two sets of limbs - they've had it. To get around it you can adjust your bolts so that you have correct tiller again, but if the limbs really are kiffed then you'll spend more time trying to get the correct tiller than you will shooting.

If the tiller doesn't change once you've set it back to where it should be (step 3) then don't worry - whatever it was that moved or changed isn't doing it anymore.