FLI: wrong phentsize

Hi!

While trying to get Paul Foley's Berkeley-DB interface (see
<http://users.actrix.co.nz/mycroft/cl.html>) to run with LispWorks
(4.2.7 pro on Linux) I arrived at this error message:

  Error: Could not register handle for external module :DBX:
   /usr/local/lib/dbx.so: ELF file's phentsize not the expected size.

What does that mean? I googled around a bit for this error message but
couldn't find anything relevant.

dbx.so is a shared library compiled with 'gcc -fPIC -shared'. CMUCL's
foreign function interface works fine with this library.

Any ideas?

Thanks,
Edi.

PS: I'm using Gentoo Linux 1.2 - kernel is 2.4.19, glibc is 2.2.5 - if
    that matters.