I had a similar problem which hit my 2 main machines at the same time. On investigating I found it to be related to the Eset personal security (guessing a recent update messed something up). To solve it I excluded VS2008 from the active browser filtering - this is in:
setup -> advanced firewall setup -> antivirus & anti spyware -> web access protection -> HTTP -> webbrowsers
Deselecting vsdev in here fixed the problem - interestingly enough disabling the firewall and antivirus / antispyware did not solve the issue, so it is worth looking for a similar setting if you are running different security software
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