My NAV popped open a warning box just now that it found a virus on my machine that can't be repaired - two in fact. And now the popup box will not go away. I had a similar problem with trojan.cachekit a while back.
NAV says it found
W32.Esbot.C at C:/winnt/system32/ssl.exe
Backdoor.ranky at C/:winnt/system32/3.tmp
I kept HIJACK THIS, and some other tools from the last time I had a similar.