You've obviously read the 'If LW will not connect' sticky...

Go to the gnutella.net file, hover your mouse over it...what size is the file?

Has this connection problem just started after updating to the latest version??

If none of the tips in the 'will not conect' thread have helped, uninstall LW (start > all programs > limewire > use the uninstall option). Now use your computer's search to look for all files & folders with limewire in the name & delete what you find BUT make sure that you're not saving downloads to a folder with limewire in the name....they could be deleted.
Restart your computer, reinstall LW using the offline installer (use the forum search for this & you'll find out how). Restart your computer again & then start LW.

Otherwise, you should post your system details as asked for in the sticky.