Perple_X data files should be downloaded from the most recent archive (e.g., Perple_X_6.7.6_data_files.zip) at 

www.perplex.ethz.ch/perplex/ibm_and_mac_archives/

The following link provides a statically linked 64 bit LINUX version of Perple_X (courtesy of Ondrej Lexa, Charles University, Prague) that is updated daily at 02:30 GMT+1 (do not use any data files included in this archive, see above)

petrol.natur.cuni.cz/~ondro/Perple_X_64bit_Linux_latest.php

If you are concerned that current version of the sources may not have compiled correctly refer to:

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

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.

The above link provides you with the latest release version of Perple_X, Ondrej's script also compiles the current development version. The development version can be accessed from:

petrol.natur.cuni.cz/~ondro/Perple_X_64bit_Linux_latest_dev.php

Do not use this version unless you have a good reason to believe it is appropriate for your purposes.