Just so you know, AVG Anti-Virus has had a history of detecting false-positives. If this ever happens to you, simply download the Priority Update and the problem should be fixed. You may need to go into the Virus Vault and restore fmod.dll from there.
In the future, if this happens and the latest update doesn't fix the problem, you can send the file to AVG denoting that it is a false-positive and they should fix it within a day at the latest. Until then, you can turn off Heuristic Analysis through the Resident Shield options.