I get similar errors in both 12.10 and 13.04:
checking for inst/npsol/linux/x86_64/gcc4.7/libnpsol.a... no
configure: error: npsol library not found
ERROR: configuration failed for package ‘OpenMx’
Why is this a problem with new versions?
Try it again now. In OpenMx 1.3.2, we added support for 32-bit and 64-bit gcc4.7 on linux. There is also a workaround here: http://openmx.psyc.virginia.edu/thread/1729#comment-4410.