Should be a quick one:
I could very well be mistaken, but it looks like the iframe initial creation point is 0,0 and input_text is initially created around the layout.width-1 area (off screen).
When creating multiple iframes, it flickers in the top left corner even with initial visibility turned off.
If correct, any chance we could move the iframe over so it flashes off screen?
(If wrong, sorry to bug you.)