Microsoft has updated their security bulletin for Internet Explorer

Subsequent to the initial release of this bulletin, a non-security issue was discovered with this patch that could affect some users - primarily consumers - under certain conditions. Specifically, the issue could cause some users to be unable to authenticate to certain Internet web sites such as subscription based sites, or MSN e-mail. This issue has been resolved, and a hot fix (813951) issued to correct it. It is important to note that this hot fix corrects a very specific non-security issue, and that the security patch discussed in this Security Bulletin was, and still is, effective in removing the vulnerabilities discussed later in this bulletin.

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