Dare I suggest something so basic & simplistic as possible help, but try deleting your FrostWire prefs folder whilst FW is closed; How to delete your FrostWire Preferences folder Perhaps this will make the difference, perhaps not. If you have any important settings then make a note of them before deleting the prefs folder. It's just a thought, as sometimes FW can behave considerably differently on one system to another due to prefs, etc.

Also make sure you have Java 1.5. If not, then remove the previous versions & replace with Java 1.5 (take the JRE)