After downloading the SPARC (not the x86) reccomended patches
for the J2SE from sunsolve,
(http://sunsolve.sun.com/pub-cgi/show.pl?target=patches/J2SE)
I discovered that J2SE_Solaris_10_Recommended.zip file contains
both SPARC and x86 patches.

The CLUSTER_README file lists the following:
--
119255-10 SunOS 5.10_x86: Install and Patch Utilities Patch
118344-05 SunOS 5.10_x86: Fault Manager Patch
119578-11 SunOS 5.10: FMA Patch
118822-26 SunOS 5.10: kernel Patch
117461-08 SunOS 5.10: ld Patch
117435-02 SunOS 5.10_x86: biosdev patch
121127-01 SunOS 5.10_x86: umountall.sh Patch
113000-07 SunOS 5.10_x86: SUNWgrub patch
118844-27 SunOS 5.10_x86: kernel Patch
--
The cluster_install script happily applied all the patches
in the patch_order file, never suspecting that this
might be a bad thing (;-))

The machine then crashed, rebooted and went into a tight
loop rebooting and crashing.

The J2SE_Solaris_10_x86_Recommended.zip file
is ok, it only contains x86 patches.
--
119255-10 SunOS 5.10_x86: Install and Patch Utilities Patch
117435-02 SunOS 5.10_x86: biosdev patch
118344-05 SunOS 5.10_x86: Fault Manager Patch
121127-01 SunOS 5.10_x86: umountall.sh Patch
113000-07 SunOS 5.10_x86: SUNWgrub patch
118844-27 SunOS 5.10_x86: kernel Patch
121208-02 SunOS 5.10_x86: ld & libc.so.1 Patch
--
I suspect we need to remove the _x86 patches from
the SPARC patch cluster as soon as possible.