Audio Problem while copying large file

I did just copy the new I9300XXELL4_I9300DBTELL1_DBT.zip (827MB) to my sgs3 via USB while listening to music. i did nothing else with that phone, screen was off. after about 1/3 of the copy process I get regular audio cuts for about 1 second. Copy process done => normal audio...

MP3 source and copy target are the internal memory.

I guess that is some memory performance / buffer problem?? I am running XXDLJ4.

anybody else ever experienced this?