So a while ago I posted about how to fix the Validation of viewstate MAC failed error. There is some really exciting news that is coming with Visual Studio 2008 Service Pack 1 and .NET Framework 3.5 Service Pack 1. One of the improvements that they made for this Service Pack is to help alleviate this issue by doing something similar to the code change recommended on my blog. So the form fields will be written out at the beginning of the form.
This means that we hopefully won’t get this error any longer from someone clicking on a page before it completely loads. You can get the Service Pack here.
Please let us know if you run into this issue after installing this.