No optimiser

I get the following error in the logs when I try and load the zend
optimiser:

Failed loading /usr/local/Zend/lib/ZendOptimizer.so:  ld.so.1:
/usr/local/apache/bin/httpd: fatal: relocation error: file
 /usr/local/Zend/lib/ZendOptimizer.so: symbol zend_v_compile_files:
referenced symbol not found


I'm using the optimiser for sparc-soloris, and I downloaded php4 from the
web site today.

My configure string is:
'./configure' '--with-apxs=/usr/local/apache/bin/apxs'
'--with-config-file-path=/usr/local/apache' '--with-mysql=/usr/local/mysql'
'--enable-versioning' '--with-system-regex' '--disable-debug'


Why?; what is zend_v_compile_files ?

Thanks

Sam