Hi Michael, Qt itself is now dependent on SSE2 so is only available as Pentium 4, it is actually built with -march=i686 but SSE is enabled.
Simplest, if you have a CPU that supports SSE2 is just to change your platform under tools in ANPM. It usually works but sometimes there are weird conflicts which can usually be fixed by right clicking the conflicting package and choosing "Get specific release" and changing to the Pentium 4 version.