fig2dev fail to export with .fig including pdf figures

If a pdf figure has been included in a .fig, it is then impossible to export to any other format. Reproducing the bug is very simple:
- first either create a simple pdf with xfig or find a pdf figure somewhere.
- then create a new .fig figure with xfig, import the pdf figure inside, save it
- finally, try to export to some format and get a nice crash.

The error message coming from gs and is:
Error: /undefined in obj
which I think indicates that the imported pdf is treated as an eps.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: transfig 1:3.2.5.d-1
ProcVersionSignature: Ubuntu 3.2.0-37.58-generic 3.2.35
Uname: Linux 3.2.0-37-generic x86_64
ApportVersion: 2.0.1-0ubuntu17.1
Architecture: amd64
Date: Tue Feb 19 19:41:19 2013
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: transfig
UpgradeStatus: Upgraded to precise on 2012-05-01 (293 days ago)