AZScanner is correct. I've also found that I need to download the .pls or.m3u file onto my PC, followed by importing them into Resco Radio. If it helps folks, I use WinAmp for the download process.
Just start listening to a live feed using WinAmp. Then hit file - save playlist. From there just choose either the .pls or .m3u format, name the file & save it to your hard drive somewhere. In Resco Radio go to All Stations - New - Import. Browse to the .pls or .m3u file you saved to your hard drive and click on the file. It will now appear as a radio station under My Radios.
Hope this helps.