[Charmedfan]

Problem fixed with help from vbulletin-germany.com!

In file clientscript/vbulletin_textedit.js find:

		if (is_ie7)
		{
			var returnvalue = window.showModalDialog("clientscript/ieprompt.html", { value: defaultval, label: dialogtxt, dir: document.dir, title: document.title }, "dialogWidth:320px; dialogHeight:150px; dialogTop:" + (parseInt(window.screenTop) + parseInt(window.event.clientY) + parseInt(document.body.scrollTop) - 100) + "px; dialogLeft:" + (parseInt(window.screenLeft) + parseInt(window.event.clientX) + parseInt(document.body.scrollLeft) - 160) + "px; resizable: No;");
		}
		else
		{
			var returnvalue = prompt(dialogtxt, defaultval);
		}

Rewrite the red marked path with you full path like that:

		if (is_ie7)
		{
			var returnvalue = window.showModalDialog("http://www.yousite.tld/forum/clientscript/ieprompt.html", { value: defaultval, label: dialogtxt, dir: document.dir, title: document.title }, "dialogWidth:320px; dialogHeight:150px; dialogTop:" + (parseInt(window.screenTop) + parseInt(window.event.clientY) + parseInt(document.body.scrollTop) - 100) + "px; dialogLeft:" + (parseInt(window.screenLeft) + parseInt(window.event.clientX) + parseInt(document.body.scrollLeft) - 160) + "px; resizable: No;");
		}
		else
		{
			var returnvalue = prompt(dialogtxt, defaultval);
		}

It is not the best solutions but a good work-arround!