Some versions of Linux have a broken pthreads library. To workaround this set the environment variable LD_ASSUME_KERNEL=2.4.19 before running LispWorks. LD_ASSUME_KERNEL allows using older versions of pthreads, some of which do not work.
LispWorks 6.1 supports any Linux distribution with glibc 2.3.3 or later.
LispWorks Release Notes and Installation Guide - 23 Dec 2011