They told me that to improve my download speed I should "up" as many times as I can.
Your PC and aMule should be running as much as possible, best 24 hours a day and 7 days a week.
Also, why do some songs download in 1 hour, others in 24 hours and others never do?
This depends of the number of sources for the file, the sources in general (if there's just one source, which is only uploading one file, you'll probably get an upload soon) and the time you waited for this file.
If it's a big file with more that one part (9.28MB) you should priorize the upload of this file. Search the wiki for credit system.
Ciao!
