I am running an XP SP3 guest. Until yesterday, internet browsing was at "normal" speeds. But then it suddenly slowed to a very, very slow crawl. This occurs for both Firefox and Internet Explorer 6 which are installed in the VM.
Checking Task Manager for either FF or IE6 shows that they both are "eating the machine" -- that is, each of them stays in excess of 85% of CPU while running.
Ping times to various servers are normal. But both browsers execute so slowly as to be unusable. Many minutes to load any page. Most websites time out before loading anything.
Obviously, something has changed, but I don't know of any changes that I made that could affect Internet bandwidth.