I suppose that other IEs show "XDR onprogress" at least once, is that right?
Anyway, this looks different from what you got in the library (I was expecting a "XDR onerror")

Sorry to bother you, but before coding a work-around I want to correctly understand why IE behaves like this.

Please do the following:
  • reload and try again the test clicking stream
  • reload and try again the test clicking poll
    • If with this new test you can get the "XDR onload" alert please try by lowering the idle timeout on our libraries until you can get a working polling session; the default value is 19000ms (you can also set it to 0 as last resort)

      ( http://www.lightstreamer.com/docs/cl...#setIdleMillis )

With this test I can verify if the class gives the error because of the long wait or if there's something else triggering the issue.

Another question, are you using InPrivate Browsing?