dinning room chairs

If the seat is rectangular, you could screw small metal angle braces in each corner. That should help stablize the seat frame.

Did you ever see those little metal pieces that have "teeth" on them, that you wrap the end of the loose rung with, and then when you stick it back in the hole, the teeth "grab" into the wood hole and hold the rung securely. It's worth a try!

Assuming they are all wood (you didn't say);
A 3/8 or 1/2-inch piece of a small, ribbed nail will do it. After glueing and putting the pieces back together, drive the pointed end of the nail into the slot along the edge of the opening. You might need to use a punch to help drive it in. Should stay put. Cut the nail piece to size before you go to drive it in. Be careful not to use too large a diameter nail or use too much force. You do't want to crack the wood around the slot.
One more thought: maybe try a different glue.

[This message has been edited by rpxlpx (edited April 23, 2001).]

[This message has been edited by rpxlpx (edited April 24, 2001).]