hey all - simple DNS is one of the weapons i use to combat the great firewall of china. obviously GFW uses many technologies to keep us from going where we want to go, but one of them is DNS poisoning - with which simple DNS can help some.
but - occasionally a "poisoned" DNS lookup done without a VPN ends up in simple DNS' cache - resulting in the pages not loading until the bad entry has expired. mostly i see this with facebook and google documents - generally things that attempt to connect frequently - before i've connected the VPN.
now - i've not found a way of clearing an individual bad entry from the cache. is there one? doing a manual lookup doesn't seem to replace the cache entry with the latest lookup's info.