NEED URGENT HELP

Let me start from the top -

  1. A few days back, Avast detected an infection when I was browsing the net using Safari. It was a trojan and it was in the cache file of safari. It was duplicating the file cache.db as cache.db_journal. After I got the notification, I could not do anything. I did not get an option to delete the file or repair it. So i tried scanning the folder in question, but avast was unable to scan the folder. Since I remembered the file name, I located it and deleted the file. After that I re-installed avast and everything seemed fine. It was working without any issue, and subsequent scans all turned up clean.
  2. Yesterday as i was browsing using safari again, I got a warning msg saying - internal error, please open avast or check system logs. At first nothing happened, I could not check any logs or i did not get any notification, today the same error occurred, but this time when i opened avast, it said the application needed to be repaired and i had to authorize it. Once it was repaired and updated it was working as usual, or so i thought. I restarted my mac and sure enough I get the same error again and again.
  3. I tried reinstalling again, but I get the same error. I am afraid that my mac has become infected and is causing the antivirus to malfunction

My mac runs on snow leopard and i have not installed windows.
Can somebody please, suggest the necessary course of action that i have to take, any help will be greatly appreciated.
Thank you in advance.

Update -
Looks like a few others are also facing the same issue, hope its fixed soon. Can anyone tell me about the trojan I found ???
I have been using avast since 2004 first on my windows PC and now on my macbook pro since 2010 and would love to continue using avast.

Hallo,
choose manual update from the menubar to get the latest VPS (younger than 5th Nov) - this will solve the problem.

Regards,
pc