Hello,
I configured Antivirus to exclude some files. When I work with them on hard drives there is no problem (even on external USB hard drives), but when I copy them to an USB flash memory the antivirus always detects them, ignoring whatever you specified on exclusions (even if you excluded all the drive).
Tested in WXP Pro SP2 & SP3 (32 bit version), Vista Business (64 bit version), with and without other antivirus software installed, with identical results in all systems (3 different computers).
Welcome to the Forum, Tonikun.
CIS does not assume anything on a removable media to be safe or permit anything to be excluded on removable media. This is by design, as the files cold easily become infected from another computer and hence infect your computer when accessed.
Thanks for the wellcome 
Well, I think excluding is not known as a safe practice, but if this option exists is for some reason. It has no sense that exclusions work well on network drives and external USB hard drives but don’t work on external USB flash drives, where the risk of infection is exactly the same ???
Network drives are normally fixed drives that can be protected. USB drives are by nature portable, and any computer they connect to may be infected.
A quote taken from this thread:
"But, removable media should not be trusted. Just to expand further on my example above, what if I excluded a file on my USB memory stick (but I don’t plug it into another computer)? My friend comes over with a cool new software program on a stick. Plugs it into my computer. On this stick is also the same file I excluded on my own stick. Also, this file is compromised (it has a virus). By allowing the exclusion on removable media, I have just become infected. Worse, this stick could be plugged into another computer and infect it. At least this way, I know I am truly protected, and there is a chance I can help my friend by informing him his file is infected.
Not trusting removable media is a good idea."
There would be less risk on a network drive because you know what security software is keeping watch over the files located there. One cannot assume the same of removable media.
Oh, I used search but I didn’t found this thread. I totally agree with “L.A.R. Grizzly” and “HeffeD” opinions. I like CIS because is powerful and configurable, I don’t like software like Norton.