Zend Optimizer Problem

Zend Optomizer 2.6.2 works ok when I use the public release, but when I try to use a custom build, I get a pretty vague exception when php-cgi.exe is launched: php-cgi.exe - Application Error The instruction at "0x7c98fea" referenced memory at "0x00000010". The memory could not be "written". Here is how I load the extension in the php.ini file, but I really don't think this is the issue since this works on the public build. zend_extension_ts="C:\php5\ZendOptimizer.dll" I'm building with 5.1.2 source using the following config: cscript /nologo configure.js --with-openssl --with-mcrypt --with-mhash --with-json --enable-sockets --with-zip --enable-soap Is there anything else I need to enable or disable to get Zend Optimizer to work?