Comment 3 for bug 554149

Michael, the tag is correct, since the problem only occurs on 64-bit systems.

FYI: Intel's EM64T architecture found in 64-bit-capable x86-compatible processors (Core 2 etc.) is basically a copy of AMD64 architecture (both are know as x86-64 for a common name). AMD was the first to deliver this architecture to market (while Intel was playing with x86-incompatible IA-64 architecture, found in Intel Itanium processors), so historically x86-64 architecture is called "amd64" in Debian, and consequently in Ubuntu. It works with both Intel and AMD 64bit processors, though the name "amd64" may cause confusion, as it seems to have done in your case.