First off, I said that I'm running a "windows 7 computer". I'm not sure if that makes a difference as to whether or not the particular fix that you suggested will work or not but in the end, I don't think that it matters; if the fix you are referring to is the BG2 Fixpack (found here), I already have that installed (unless you're talking about installing it again).
As said previously, I installed the entire standard version of the BiG World installer which, upon looking back at my Weidu.log, installed the BG2 Fixpack.