I didn’t mention any ini files so not sure what you’re doing with that…I am at work and didn’t know the exact filename, month122004.inf is the correct filename to move/rename before attempting to convert the 122004lg.txt file.
Watch out for a numbered file, ie. 18, in your logfiles directory, a sure sign that the convert failed.
edit: Here’s a thread that explains how to fix the trend data: http://discourse.weather-watch.com/t/10186