Is there a trick to sizing controls for wx.lib.CUstomTreeCtrl?  I've been trying to create my own custom controls (just panels with sub-controls in them) and add them as items in my CustomTreeCtrl, but when the tree renders, it's as if the panels aren't expanded to the appropriate size.  I can set the panel size manually by using SetSize() but if I do that, the tree doesn't seem to be aware of the size (the rows aren't scaled to the appropriate size) and the items are rendered on top of each other.  I've tried to override DoGetBestSize() but it seems to not have any effect.
Can you put a self contained sample code and we can try to fix that.
Have you tried adding custom items which return correct height for your panel?
Sizing controls for items in wx.lib.CustomTreeCtrl