This is the only reference I can find to Money orders:
"ATTENTION: We are unfortunately unable to accept personal checks. You may purchase LimeWire PRO with a money order issued in US Dollars from any bank in the world."
So please confirm that you are going to the correct site:
http://www.limewire.com/english/content/download.shtml and give us a link to the page that says otherwise.
You should get an e-mail to say I have replied to your post, with a link directing you back here. (this is for others who may stumble across this thread)