If you have Pro, you would have received an email from them. Check your email for past such emails. Pro support only lasts for 6 months unless you purchased their 12 month support, or their limited version with no support.

Try reinstalling LW using 'this' offline version: http://www9.limewire.com/download/LimeWireWin-full.exe. This is the LW Basic version however. Perhaps you need to check when you purchased pro as to whether you are able to get another copy.