I would do a search on your system for all binkw32.dll and make sure that you are not loading the wrong binkw32.dll instead of the one that is shipped with entrenchment. This could happen due to your path variable or something in the registry, but most executables should look in the current working directory for all dynamic linked libraries before searching externally. This became a standard in software development around the release of WinXP OS. If I remember correctly this has to be done for microsoft certification.
You can also try to search the internet for bink32w.dll and try to find the latest release of the library and rename the one in entrenchment directory and copy the one from internet in place. This will just insure the library shipped with entrenchment is not corrupted or a incorrect version. ( I highly doubt this will be the case, but it is the fastest test).
