Like Inject said, Audacity can fix it, you can download it here:
http://audacity.sourceforge.net/download/Anyway, to help, start up audacity, open up the sound you need, and check the bottom left of Audacity, it should say "Project Rate", and have a dropdown bar with a large number (default 48000), change this to 44100 and save it, then export it as either .mp3 or .wav, and try again.
If it's not working, PM me and I'll try to help further.