No matter how many times I verify the integrity of the game cache via Steam, it always reports 1 file failed and will be re-acquired which it then does. Repeating the check results in it re-acquiring the 1 file again. Is there a solution to this or is it safe to ignore?

I installed via retail disc.

Having the same problem, but with the Steam version.

My steam copy always fails on 1 file. Check your gamevalidation.log in your steam directory. The file should be installscriot.vdf or something like that.
This is a common issue and shouldnt effect the game. My copy runs fine. I believe theres a fix for it. I never bothered with it. Try googling it.