We have, just in case, added a WWSafe.pm module to the WeBWorK software which can be used if your system's version of Safe is not compatible with WeBWorK. (To use it change the use Safe; line in pg/lib/WeBWorK/PG/Translator.pm to use WWSafe; )
The change log in the CPAN repository at http://search.cpan.org/~rgarcia/Safe-2.29/ reads:
2.29 Sun Oct 31 2010 - Add &version::vxs::VCMP to Safe's default share 2.28 Mon Sep 13 2010 - Avoid infinite loop in _find_code_refs. Patch by Yasushi Nakajima (rt.cpan.org #61262)-- Mike