There was a patch released a few days ago, version 1.6b this patch was released for bugs related to the MacOS but the Linux port resolved the small window issue where you cannot see the Next button.


Here is the Post from the LimeWire Team:

There was also a bug that would occasionally arise on various platforms with accessing some configuration files on startup.

It would be a tremendous help if anyone who has a spare moment could give the new installers a try and report any problems back on the forum.

Many thanks to all.

-LimeWire Team

Here is the patch you will need to fix your issue:
http://www.limewire.com/beta/1.6b/

Enjoy!