After patching 11.1.0.7.0 to 11.1.0.6.0, db std edition become enterprise edition

 Hi All, I just installed a Oracle 11gR1 onto a Sun Sparc T5120 using the installer from technet. I selected the Oracle DB Standard Edition during the installation process, and I performed "select * from the v$version", it show it is std edition, however after I done the 11.1.0.7 patching, and the result from "select * from the v$version" is "Oracle Database 11g Enterprise Edition Release 11.1.0.7.0 - 64bit Production", how come the patch updated and upgraded my db edition ?
Spec:
SunOS 5.10 Generic_141414-10 sun4v sparc SUNW,SPARC-Enterprise-T5120
4G RAM


Thanks,
Keng Heng. Chan