Some people found how to resolve those issues.
According that you've installed jas 10.4.7 AMD DVD
Download Maxxuss amd enabler cpuid patches
or from here
Now decompress AMD_Enabler.zip in the Desktop.
open up the terminal (finder->applications->utilities)
sudo ./patcher cpuid_patches.txt
Enter your password when required.
Reboot & enjoy
Many thanks to: JaS, Maxxuss, wcarson , cmf.
Apple system profiler don't shows SSE3, even if you have a cpu with SSe3 instructions set.
If you have SSE3, you can download Itunes 7.0.1. It works, meaning SSE3 is enabled...
I'm working a CPU-Z app under Mac OS X....
it's only a matter of time...