It's probably the crappy limewire player, it has never been reliable...
You could try deleting your preference folder/s and see if that get's it going again...
This will reset your configurations back to default and get rid of any corruption that may of happened...
Fixes for Limewire when LW isn't operating as it should LimeWire Pref Folder in Vista
If that doest help try using a third party player ie. itunes or WMP etc...
To disable LW player go to Tools > Options > Player and untick the box and select apply...
To make WMP your default player
Go to your shared folder (outside of Limewire) you will find this folder by clicking on one of your files in your LW library and clicking explore...
Right click on one of your MP3 files
Select open with
Select choose program
select WMP
and tick the box that says always use this program to open this file type
Select OK