Statically linked 64 bit LINUX versions of Perple_X, courtesy of Ondrej Lexa, Charles University, Prague, are at 

petrol.natur.cuni.cz/~ondro/perplex

These versions are updated daily at 02:30 GMT+1.

If you want to verify that you are using the current (release) version of Perple_X, then compare the source date printed to the user console when any Perple_X program is executed with the last update in www.perplex.ethz.ch/perplex_updates.html. If the binary sources are older than the last source update, then please contact me (james dot connolly at erdw dot ethz dot ch) and I will correct the problem.