You may want to try playing INFA under a 3.6.9 build, which it was released for. 3.6.10 has more stringent standards regarding errors, so it may say 'whoa now' at problems that 3.6.9 would just kind of brush under the carpet.
I believe Mobius is working on a remade version of INFA called INFASA, which I'm personally pretty excited about. You may want to try out other mods and wait until he releases that.
INF and INF:A have gotten a bad rap over the years, but they really are a pretty good time.