Firebug displaying SenderString is undefined when using PostBack Ritalin with ASP.NET 4

As you might notice soon enough, a change in ASP.NET 4’s client-side API breaks versions 0.8 through 1.0 of PostBack Ritalin. Using those older versions of the control with ASP.NET 4 will throw a JavaScript error during BeginRequest and break asynchronous postbacks as a result.

PostBack Ritalin v1.1 works around that issue, and is also backward-compatible with ASP.NET 2.0 and 3.5. It’s available on the PostBack Ritalin project page now.

Special thanks to Maciej Borzecki for reporting the issue to me early enough to have a fix ready today.