Raymond Toy and others fixed this bug about two weeks ago---see bug
1036900
http://sourceforge.net/tracker/index.php?func=detail&aid=1036900&group_id=4933&atid=104933
The fix is in 5.9.1.1cvs.
(%i5) limit(2^n/3^n,n,inf);
(%o5) 0
(%i6) build_info();
Maxima version: 5.9.1.1cvs
Maxima build date: 12:21 10/20/2004
host type: i686-pc-mingw32
lisp-implementation-type: Kyoto Common Lisp
lisp-implementation-version: GCL 2.6.5
Barton