Basically, the newest version of HKL2000 won't run on Linux machines that do not have the libg2c.so.0 library (part of gcc3) in /usr/lib/ .
This no doubt qualifies as an obvious question, but have you tried /usr/local/lib? That is often automatically searched for libraries on Linux systems, and is often used as a resting place for obsolete libraries for that reason.
It's preferable, if they're available for your flavor of Linux, to use compatibility packages as Professor Rowlett mentions. You'll probably need "compat-g77", or something similar, as libg2c is the old Fortran compatibility library for GCC.
-- Michael Strickler, Ph.D. Research Specialist Center for Structural Biology Yale University 260 Whitney Ave, 355C JWG PO Box 208114 New Haven, CT 06520-8114