MMF2 Updater failed

just now i tried to install MMF2 (Standard Version) onto my windows vista PC, the install went fine.
But when i tried to run the updater it started to update then around 30% it stopped, then came up with.

"Multimedia Fusion 2 has not been totally updated because of the following reason.
Cannot open C\Program Files\Multimedia Fusion 2\Data Runtime\Unist.$$A"
You will have to run this utility again to completely update Multimedia Fusion 2"

As soon as ths happened, my anti-virus registered and dealt with a trojan, (i repeated this three times, and this happened three times the same, i thnk this is because it did not update so registered it as a threat)

I have Administrative rights, and the disk was a legal copy of Multimedia Fusion 2, bought in 2008 from Clickteam

Can anyone shed some light onto this please? (or know if Clickteam are doing something with their updater that is causing this)

Thanks in advance.

It sounds like your antivirus is giving a false positive, treating one of the installation files as a threat. Which one do you use?

It's McAfee Plusnet Protect.
I thought that too y'know.

C\Program Files\Multimedia Fusion 2\Data Runtime\Unist.$$A"

Add an exception to your Realtime Shields so that the program doesn't scan that directory.

C\Program Files\Multimedia Fusion 2

Stop there and you should be safe to install extensions and update as normal.

Uninst.$$A corresponds to Uninst.exe (64kb).
Probably some trojan writes a file similar to that one, and McAfee mistakes it for the trojan.
Alternatively, you have a trojan, which is injecting its code into the EXE file being written; this might be the case if other people using Plusnet Protect (or whatever the non-branded name for it is) do not have this issue.
So do a virus check just to be sure! :)