Sharepoint: customizing newform.aspx nightmare

this approach will give you trouble using the file attachment feature and will prompted you with an error message when you try to attach a file in a custom form on the Web site in Windows SharePoint Services 3.0.

“This form was customized not working with attachment"

solution can be found here: Here

or if you did not remove the original listform but just hide it you'll probably get this error:

"attachment problem can't move focus to the control because it is invincible.."

solution can be found here: here
or hotfix

update: you can resolved the issue by installing service pack 2 for the sharepoint 2007, windows sharepoint services and your sharepoint designer 2007.

and...the next problem is when you upload a file the interface doesn't change but when you close it you can find that it is already uploaded.