Beneath the join list you can see the option: "Insert silence between MP3 track, s". A small field on the right contains 0, which means that there will be no pauses. If you want some, please change the value to an appropriate number of seconds.
One of the main reasons I bought Visual MP3 Splitter was the Silent detection tool. It worked very well and was a great time saver when splitting several mp3 files containing whole CD's.
I must also mention that the team at ManiacTools was very helpful when I got in to some trouble with a file that had a garbled header. I don't how they did it but now I split that file too...Bertil Palmqvist, Sweden