Sharepoint: Modifying newform.aspx and attach button does not work

Question

I modified the newform.aspx page in Sharepoint 2007 Designer for an announcment list as demonstrated in the following page http://sharepoint.mindsharpblogs.com/DanielG/Lists/Categories/Category.aspx?Name=SharePoint%20Designer
I have hidden (<IsVisible>false</IsVisible>) the original form web part.
When I try to press the Attach File link to attach a file I get a Javascript error:

Webpage error details

User Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0; InfoPath.2; .NET CLR 2.0.50727; InfoPath.1; .NET CLR 1.1.4322; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; MS-RTC LM 8; MSN OptimizedIE8;ENUS) Timestamp: Mon, 13 Sep 2010 12:12:02 UTC

Message: Can't move focus to the control because it is invisible, not enabled, or of a type that does not accept the focus. Line: 5747 Char: 2 Code: 0 URI: http://server-x/_layouts/1033/form.js?rev=df60y6YolDjUVbi91%2BZw%2Fg%3D%3D

Message: Can't move focus to the control because it is invisible, not enabled, or of a type that does not accept the focus. Line: 5747 Char: 2 Code: 0 URI: http://server-x/_layouts/1033/form.js?rev=df60y6YolDjUVbi91%2BZw%2Fg%3D%3D

Answer 1

I just deleted the form web part as opposed to hidding it and it seemed to work now.