I have tried to reproduce the mentioned issue with the RadButton but to no avail. You can watch a short video in the attached archive and then tell me what I am missing with the test.
Note that in Q3 2013 there is an issue with the clicking of the RadButton when Enter keys is pressed inside password TextBox. The issue has already been logged in our feedback portal here, so that you can monitor, comment, vote on it and find a workaround there.
If the mentioned issue, however, is different than the above one, could you please try to reproduce it with the attached VS example and then send it back to us, so that we can make an investigation further? Could you also tell us, which are the problematic browsers under which the issue is observed, as well as their versions?
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