There is a known bug with IE7 where absolute positioned elements
that don't have a width specified can trigger it to display a
horizontal scrollbar even though it is unnecessary.
The IFrame Shim that livepipe uses seems to trigger this bug
mostly in cases where the shim is shown before it is given
position. There were 2 places that were giving me problems with
Control.Modal.
The first was with the overlay. The positionIFrameShim function
of Control.Overlay looks like:
positionIFrameShim: function(){
if(Control.Overlay.container.visible())
Control.Overlay.iFrameShim.positionUnder(Control.Overlay.container);
}
The problem is that on the first time the overlay is shown, this
position function is called before the overlay is made visible and
thus the positionUnder function of the IFrameShim class is not
called. In IE7 this can trigger the scrollbar bug. I commented out
the if statement but there is probably a more suitable
solution.
The second place I encountered a problem was with the actual
modal window itself. A scrollbar would appear momentarily and then
go away. The updateIFrameShimZIndex function is being called twice
when the window first opens and you are using the fade option.
The finishOpen function starts the fade effect which calls
updateIFrameShimZIndex on completion. The finishOpen function calls
the position function after it starts the effect however. It is
unlikely but the effect could finish before position is called,
thus triggering the scrollbar bug because the position of the
iframe is set to the undefined position of the window. I thus moved
the call to position up to the top of the finishOpen call so we
know the window has been positioned before showing it.
The end of the position function also calls
updateIFrameShimZIndex though. Strangely, when this is called and
the window is not actually visible yet, the IE7 bug is triggered
even though the element has in fact been positioned. I thus changed
the end of the position function to read:
if(this.iFrameShim && this.isOpen)
this.updateIFrameShimZIndex();
This ensures the window is open before trying to position the
shim.
Nathan L Smith