from http://whitemagiclabs.com/blog/

"So why did themes work on 10.4.1-10.4.3×86 just fine? Why did Apple create a second resource file in 10.4.4? This probably has something to do with the way Apple protected OS X from being loaded on generic PC’s. There was a big internal change in 10.4.4 (hint: this change lifted the requirement of SSE3 for running OS X on a generic PC for most tasks… SSE3 is required for one thing specifically…)"

"this change lifted" what does this mean, lifted, as in removed?

what one specific thing requires SSE3?