Execute 2 ipo animations in the same time (with "add")

Hello,
I have a little animation problem…
I want to execute, for example the animation from frame 0 to 20 and 30 to 50 in the same time with “add”.
But it doesn’t work with 2.49 and with 2.5…Is it normal ?
Little example blends :
2.49 : http://www.mediafire.com/?6u9ksa2ac7aaqlp
2.5 : http://www.mediafire.com/?0yt7w5n5adyxdot

yes, this is normal. If you want to combine IPOs, you can use two objects. Each one with its own IPO. Just parent the objects together.
The child will inherit the transformation from the parent.

Ok…But I set the start and endFrame with Python…So I have to hade to objects with the same IPO keys ?
I’ll test it, thx