Opera 9.5 breaks ASP.NET Validator on ASP.NET 2.0/3.5

Bug report by Geir Kiste Axezz. June 28 2008, updated August 23 2008

Bug description

When entering text in the zip code text field, and you tab to the next field, the City field, it should display a guid string.

This bug is present in Opera 9.50. and 9.51.
It was fixed in Opera 9.52.
It is not present in Opera 9.27.
This bug is apparent in ASP.NET 2.0 and 3.5. It will work as intented on ASP.NET 1.1

Info and workaround

The automatically generated Validator javascript onchange event is not triggering. This can also be confirmed by adding a simple onchange event: zipCodeTextBox.Attributes.Add("onchange", "alert('Hello')"). Workaround: Set EnableClientScript=False on Validator, but this is not a good solution as client side validation is then not enabled of course...

Test Case