Ubuntu 11.04 Natty AMD64 make problems
general-beck@gblive:/userdata/Bitcoin/cpuminer-1.0.1$ CFLAGS="-O3 -Wall -msse2" ./configure
...
I think the problem is that the first option in cflags should be 03 (with a zero) NOT O3 (with the letter 'o'). Hope that helps.