Hi...
We need answers to the usual questions...
What Operating System
What installed memory
What 'player' are you using
Have you noticed any pattern to the 'sources' of such 'bad' files ?
And, are you at all referring to 'monitoring' type listening before a download is completed ?
Is your Hard Disc Drive properly defragmented ?
Are you running any other CPU usage intensive applications at the same time ?
And more... But we will wait for your first answers !