Thank you for your help!! I'm very glad about it and I'm very interested in the code snippet which was probably longer than 10 lines of code.
Could you post it again somewhere and post the link here?
To implement such an timer is an idea. Although I think that 5-10 minutes are may be a little bit to much in some cases. There are probably podcasts with short episodes. If someone is playing/downloading such an episode and he/she wants to play or download the file again then the file would be locked.
One of my ideas is to regulate the counter by the User Agent string. For instance if I download an m4v file with my Ubuntu computer then the first User Agent string of the download would be the one of the browser followed by several from the browser plugin. That is a recognisable pattern which can be used. But so far I know only this special pattern.
That is why it would be great if you could visit my test post with your iPhone/iPad/iPod Touch and leave one or two trace in my statistics. (In the last days my stats method was Counts Only. But now it is Full again.)