I know for sure, I have Intel Core 2 Quad Q6700, 2.66 GHz, overclocked to 2.72 GHz.
Even Processor ID Utility is stating that. It reports SSE3 is the highest supported streaming extension. Other information it provides is SSE4=no, AVX=no, AES new instructions=no, Virtualization techs.=yes, hyperthreading=no, I64Arch.=yes; CPUID data: type=0, family=6, model=F, Stepping=B, and revision=B6; LGA775 socket; NX bit=yes, Enhanced Halt State=yes; Chipset ID=2916.
Running MSVC 2010, on Vista Ultimate x64.
There should be filed a bug report.