Right, must be the first time but my S3 run out of juice for the first time. Music kept stopping to play and I presumed corrupt MP3s. After a while I noticed that it mainly seemed to be doing that when I was browsing the web. Look at memory usage showed almost 800MB used out of 832MB available. Cleared RAM and all good.
Having said that though. Clearly down to bad programming as it made no difference whether apps were running in the background or not. Only active apps are chrome and music player. So same point really. If an app has a memory leak then more Ram would just mean the app can use now to 'leak'
It's like Microsoft SQL Server. You got 4GB of Ram, it uses 100%. You upgrade to 32GB of Ram, it uses it. So unless you know that you can limit SQL to use x-amount of Ram, you will always think it runs out and you throw more DIMMS at it (real life example happened two days ago).