I helped someone who had the same problem with F-secure a few weeks back, and I'm fairly sure it does have a whitelist of sorts if it continues to give you trouble.
If you go into the settings and look under "Virus and spyware scanning", you should be able to find an "Open excluded items list" link. If you switch to the "Objects" tab in that window, check the "Exclude objects" option, add the Tribes2 directory to that list, and it should be excluded from their real-time scanning.
Yep, I did this on my laptop, but I think that at one point the game got out from whitelist by itself and then the F-Secure blocked it again..
I got the above IFC22.DLL thing to work, so thanks for that. I also sent F-Secure a false positive report and they said they will whitelist it in some update