Converting 59.94 to 23.98 without slowdown

I have a massive project with about half the footage at 59.94 and the other half at 23.98. We ran a dual system for sound which was recorded at 23.98 so I need to convert all 59.94 clips to 23.98 to be able to sync with the sound.

While researching different methods I found this tutorial http://www.creativecow.net/articles/rossshane/dvprohd/index.html which describes how to convert 59.94 to 23.98 using DVCPRO HD Frame Rate Converter. When the Framerate Converter is used in the tutorial it slows the footage down to 23.98 making it play in slow motion.

I followed this tutorial precisely and when I do it the footage is conformed to 23.98 without slowdown; this is exactly what I want.

*I have two questions:*
1) Do you know why the DVCPRO HD Frame Rate Converter is giving me different results than the tutorial?

2) If I have about 250 clips to convert, would the DVCPRO HD Frame Rate Converter be the best way to do it and if not, what would you suggest?

Thank you all for your help!