Problems with Media Player over Internet

[Skeeeve]

I use a talk radio website to download archives of talk show programs and play them on my PC using Media Player v10. Every day, the radio station overwrites their archives with the content from that day.

For example, the programs are divided into 1 hour segments, 1:00 AM, 2:00 AM, etc. If I visited the site at say, 5:00 PM on a Tuesday, I know I could download Monday's 9:00 AM program. However, if I selected the 7:00 PM slot, I would get Monday's content. The station names the mp3 files exactly the same each hour, no matter what day it is.

The problem I am having is that I am still getting last week's broadcast. It's obvious that there is a copy of the file saved on my system somewhere and that by visiting the site again, Media Player gets confused and says "you want to download 200am.wmv? I already have that in my cache, here it is" and it's wrong.

How do I correct this problem?

I am using Firefox, but this problem has occured with Internet Explorer as well.

Thanks.