Not sure if this is related, but, I know that if you plan to programatically change an anchored control's position and size, you must first set it's Anchor to 0, make the appropriate change, then set the Anchor back to it's initial value. If you don't, the changes don't get recognized.

Mike

>>How container B resizes relative to the form resize? How do you expect Container A to resize?
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>In height. This is now interesting, my Conatiner B is 140 pixels wide and I have sized Conatiner A to be 136 pixels (left = 2 so I have a margin on both sides of A)
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>I had previously dragged-dropped Container B on my form and resized to 150 pixels wide, eveything else inside is not touched, esp. not the later added Container A, so it is 10 pixels short when the form is opened at design time.
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>Now at run-time only vertical resize happens of Container B.