Random Music - number of titles

Hi
I really like the 'random music' function. When i go into it there is an option 'all tracks' which is exactly what i want - to play all songs in my library randomly. I have several thousand titles in my library but when i hit 'all tracks' and then scroll through the tracks there is only around 100 or so in the list.

Does this function replace a track as it plays it or is 100 or so the limit in this function?

thanks in advance for your help

It changes every single time you request the virtual folder.