Media Player Problem

Here is my problem with Media Player.

New Song
Insert a Media Player and select an MP3

Now, on the Timeline I show the audio file.

Now, if I delete and select another MP3 or select another MP3 instead, then it doesn’t show in the Timeline and I can not play it anymore.

The solution I have is to delete the Media Player and create a New one.

I know it is not supposed to work this way. Is it something on my system??