When submitting the FormExample.xsp in IE9 you get a JavaScript error from Dojo:
{var _2e=_2d.getAttribute("widgetId")
xspClientDojoUI.js, line 4 character 456
Seems to think that the SWUploader is a Domino widget and fails when there's no widgetid-property.
This is only in IE9 (IE9 as IE8/IE7 works fine).
Domino 8.5.3
Windows 7 64bit
A simple solution would be to remove the node after the uploads are done, but I haven't investigated further.