Problem: crazy music speed while hosting

[Kortiv]

Hello guys i'm not really expert with Winamp/shoutcast, however some months ago i used it for broadcast my own radio channel and it worked perfectly (i still have same pc and connection of then).
This summer i installed Winamp again and there is a problem i can't solve alone
I configured winamp and shoutcast as ever but this time, when i broadcast mp3 files on radio, they start with a long delay, with an extreme speed in reproduction and the audio seems damaged. (if i broadcast my microphone input or my stereo mix everything it's fine)
I also tried to install these softwares on my friend's pc and they works there, i updated my audio drivers but the problem is still there.

Anyone had my same problem? have you some idea? i hope for help guys

P.S. I use win7 (32bit) - audio board is Realteck ALC887 - my net upload 0.80 Mbps