Hi we've found the problem.
Java 1.6 implements its own SystemTray and some other functionalities that we used to take from JDIC.
Please download this patched release to solve the problem, it will run fine with java 1.6.0

http://www.frostwire.com/frostwire/4...1.5-1.i586.deb
http://www.frostwire.com/frostwire/4...5-1.noarch.rpm
http://www.frostwire.com/frostwire/4....noarch.tar.gz