The problem you're having with v.4 is probably a Java version issue. LW runs using Java (Java & the Gnutella network are changing so they need to keep up as does LW.) Check you Java version. For OS 9.1 you'll need
Java MRJ 2.2.5
Why not update your OS to 9.2.2 so you can use
Java MRJ 2.2.6 & you should have many less problems.
On this forum I found this note:
the old free installers for all platforms are stuffed into one large archive (~70mb).
older Limewire versions has the 3.8.10 and .11 installers. So if you insist on an old version you will find it here.
Did you know you can run OS X on your computer?