how does libtool order -Wl,--rpath?

[Ted Irons]

I am trying to pick up a local installed copy of libNITF in 
/volume19/ix86-linux/lib rather
than the copy of libNITF in /swl/ix86-linux/lib.  /swl/ix86-linux/lib is needed 
for other
libraries; it also contains gcc, etc.  LD_LIBRARY_PATH is set to 
/swl/ix86-linux/lib.

The call to libtool yields:
/bin/sh ../../libtool --mode=link g++  ... -o libXWImage.la \
        -rpath /volume19/ix86-linux/lib  \
        ... AvirisImageFile.lo ... \
        -L/volume19/ix86-linux/lib -L/swl/ix86-linux/lib ... -lNITF ...

What libtool invokes is:
g++ -shared ... .libs/AvirisImageFile.o ... \
        -Wl,--rpath -Wl,/swl/ix86-linux/lib -Wl,--rpath 
-Wl,/volume19/ix86-linux/lib \
        ... -L/swl/ix86-linux/lib/. ... -L/volume19/ix86-linux/lib \
        ... /volume19/ix86-linux/lib/libNITF.so ... -o 
.libs/libXWImage.so.1.1.13

As a result 'ldd libXWImage.so.1.1.13' indicates that libXWImages
is (for me, incorrectly) picking up the libNITF from /swl/ix86-linux/lib.
Note this happens in spite of the presence of 
'/volume19/ix86-linux/lib/libNITF.so'!

If I run the 'g++ -shared ...' line with the -Wl,--rpath's reversed (so that
'-Wl,--rpath -Wl,/volume19/ix86-linux/lib' appears first) I get the result
that I want.

So how does libtool determine the order of the -Wl,--rpath's in the line
that it invokes?  I have looked at the libtool documentation and libtool
mail archives, but have not found anything.

It seems to me that libtool, to begin with,  should order the -Wl,--rpath's to
match the order of the -L's found in LDFLAGS (or LIBS).

I am using autoconf-2.57, automake-1.7.5, and
libtool-1.5 on linux, solaris, and irix6.5 systems.

- Ted