I have always filled my iPod using the iTunes software, which whilst basic, is reliable. Because my music collection has grown, I needed to convert my MP3's to get them onto my 30GB iPod. So I purchased your software.
I spent 4 hours making a playlist to sync with the iPod. I then set it running to sync. 4 hours into a 5 hour transfer your program throws an error, closes itself, and corrupts the iPod so it shows 25Gb or "other" files on it, but no sign of any music or anything. So I use the iTunes to reset the device to it's factory settings, as that seems to be the only way to recover the lost space.
I then try the sync again, this time it got four and a half hours into the transfer, and did exactly the same thing. I now have only one hour before I must leave on a two week sales trip, and no time to fill my iPod.