Check out the thread below and try the fixes, It may help I had the speed issue long ago and the limewire preference folder one helped me.
http://www.gnutellaforums.com/showth...threadid=36420
And I don't know if you got the porn issue fixed but you might try the following.
Block the following IP addresses, you can do this by going to tools/options/filters/host and typing the following IP addresses in and block them. I have done this and I no longer get the porn results when searching for files that have nothing to do with porn.
70.85.111.131
70.86.48.178
70.86.48.218
70.86.48.202
So far there are only 4 that are responsible for the porn results that I have been able to find. But the problem will probably get worse before it gets better.