Msg#: 4156937 posted 9:19 am on Jun 23, 2010 (gmt 0)
As topr8 says, that is how it should work. At a guess you had been using a browser that had previously been forgiving but a bug fix or upgrade has corrected this.
I had a similar problem some years ago with tables. One browser assumed a /tr when it found a new row but another didn't. I had been copying and pasting rows and hadn't noticed that I had lost the /tr.
This is why you should always test your site in IE and at least one other browser.