I never use the HOSTS immunization anymore. It's just grown too large and Windows has issues. Right when you plug in the network cable watch your DNS service spike to 100% for sometimes 20-30 seconds when normally it should only have a little bit of activity for a second or two. It's also affected by everyday browsing by missing packets and dropping pictures from loading. It's especially bad when you try using a MiFi, WiFi, or even dial up. It's grown to what, 450KB?
Anyway, I'm sure everyone already knows this by now.