I investigated this and I do not understand why you use the speedbutton.ElementID? There is no HTML template associated with this form, so it doesn't make sense to set the ElementID.
Also, when you set this ElementID, when you create a second instance of the control referring to the same, existing ElementID, the control would be mapped on the already existing control, i.e. the one already on the first tab.
So, if you do not map the speedbutton on existing HTML in the form HTML template, do NOT use ElementID.