Update: Microsoft Issues Press Release on Site Access Problems
Microsoft denies third-party involvement or security vulnerability.
Microsoft has issued a press release regarding site access problems, citing that the issue was due to an internal technical error, not as a result of a third-party involvement, such as a hacker or software incompatibility, nor a security vulnerability, as has been speculated. Microsoft says the problem has been resolved, but access to its training and certification site was still unavailable as of 9 a.m. PDT.
To read the announcement, go to http://www.microsoft.com/info/siteaccess.htm.