Install OpenCascade on RHEL5

I try to install OpenCascade on RHEL5 (32bit and 64bit) and I am not successful.

First at configure stage I see some warnings:

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#./configure $flags --prefix=/opt/OpenCascade6.3.0
.
.
.
.
checking X11/extensions/multibuf.h presence... yes
configure: WARNING: X11/extensions/multibuf.h: present but cannot be compiled
configure: WARNING: X11/extensions/multibuf.h: check for missing prerequisite headers?
configure: WARNING: X11/extensions/multibuf.h: proceeding with the preprocessor's result
configure: WARNING: ## ------------------------------------ ##
configure: WARNING: ## Report this to bug-autoconf@gnu.org. ##
configure: WARNING: ## ------------------------------------ ##
checking for X11/extensions/multibuf.h... yes
.
.
.
.

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This is a bug for sure. Then I try to compile the sources and I get:

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# make
cd . && /bin/sh /compile/OpenCASCADE6.3.0/ros/make/missing --run aclocal-1.7
cd . && \
/bin/sh /compile/OpenCASCADE6.3.0/ros/make/missing --run automake-1.7 --foreign Makefile
Makefile.am:3: directory should not contain `/'
make: *** [Makefile.in] Error 1

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However, if a issue a second make the compilation seems to work but when I do make install I believe a lot of libraries are left in the build location. This is what I have in lib after make install:

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#pwd
/opt/OpenCascade6.3.0/lib
# ls -al
total 16780
drwxr-xr-x 2 root root 4096 Jan 18 23:13 .
drwxr-xr-x 8 root root 4096 Jan 18 11:55 ..
lrwxrwxrwx 1 root root 16 Jan 18 23:13 libTKernel -> libTKernel.0.0.0
lrwxrwxrwx 1 root root 16 Jan 18 23:13 libTKernel.0 -> libTKernel.0.0.0
-rwxr-xr-x 1 root root 17120955 Jan 18 23:13 libTKernel.0.0.0
-rwxr-xr-x 1 root root 733 Jan 18 23:13 libTKernel.la

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For completeness I am also attaching the contents of a file which sets up the flag and the environment variables.

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flags=
flags="$flag --with-gl-include=/usr/include"
flags="$flags --with-gl-library=/usr/lib"
flags="$flags --with-tcl=/usr/lib"
flags="$flags --with-tk=/usr/lib "
flags="$flags --with-xmu-include=/usr/include"
flags="$flags --with-xmu-library=/usr/lib"
flags="$flags --with-java-include=/usr/lib/jvm/java-1.6.0-sun-1.6.0.11/include"
flags="$flags --enable-static=no"
flags="$flags --enable-shared=yes"
flags="$flags --enable-debug=yes"
flags="$flags --enable-production=yes"
flags="$flags --enable-draw=yes"
flags="$flags --enable-wok=yes"
flags="$flags --enable-wrappers=yes"

export flags
export DISTRIBUTIVE_DIR=/compile/OpenCASCADE6.3.0/ros
export CASROOT=${DISTRIBUTIVE_DIR}

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Could anyone help me out? Is anybody using OpenCascade on RHEL5? To me it looks like the configuration files are corrupted. I see a lot of compiled libs with an 'U' at the end of the file, e.g.,

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# pwd
/opt/compile/OpenCASCADE6.3.0/ros/adm/make/TKBinXCAF/.libs
# ls -al
total 896
drwxr-xr-x 2 root root 4096 Jan 18 23:24 .
drwxrwxrwx 4 root root 4096 Jan 18 00:22 ..
lrwxrwxrwx 1 root root 18 Jan 18 00:22 libTKBinXCAF -> libTKBinXCAF.0.0.0
lrwxrwxrwx 1 root root 18 Jan 18 00:22 libTKBinXCAF.0 -> libTKBinXCAF.0.0.0
-rwxr-xr-x 1 root root 872332 Jan 18 00:22 libTKBinXCAF.0.0.0U
lrwxrwxrwx 1 root root 18 Jan 18 00:22 libTKBinXCAF.la -> ../libTKBinXCAF.la
-rw-r--r-- 1 root root 1510 Jan 18 00:22 libTKBinXCAF.lai

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Thank you in advance for your help.

Best regards,
Dragos