Ticket #7202 (closed bug: fixed)
Linux bindists don't work on new distros
All of the binary distributions are built on systems that have libgmp.so.3. On newer Linux distros (I use Fedora 17), libgmp.so.3 is no longer available because it's been superseded by a new version of GMP. This problem will probably become more widespread as uptake of the new version of GMP spreads.
One possible workaround would be to ship with a copy of libgmp.so.3 that is installed along with GHC if there isn't already a copy present.