Not sure on the bug, but check line 72. Everywhere else the dialog is referenced using "mp3player," but in this one line you have just "mp3."
Also, I see under the alias randomsong you're setting global variables when you could get by using the temporary /var function. %mp3.num and %mp3.ran2 can be set with a var instead, since they aren't ever used outside the alias and only set up data for the next script line.
Fixed line 72. I was converting the dialog/commands before posting and I missed one.
Yeah I modified that on my local copy trying to fix the 'folder issue' I'm having. Nothing I've tried seems to work in making the script remember to open from the folder I choose.. keeps defaulting to wherever I last opened an mp3... well, not always. it decides randomly when it's going to start doing that and I have to unload/load the mrc file to get it going again.