Monday, November 3, 2008

Invalid postback or callback argument. Event validation is enabled using in configuration ...

there's a nice explication:
http://msdn.microsoft.com/en-us/library/df6hth3s(VS.80).aspx

BUT you can check if in the IIS is set the correct .NET version. Using 1.1 and having 2.0 set gave me this error when using a custom control with a button in a repeater. I've changed the settings and worked fine, without changing in code.
I've changed back the code, took out the repeater and it worked fine even when the .NET version was not set correct.