I have downloaded swfdec 0.5.90 and swfdec-mozilla 0.5.90, compiled on ubuntu gutsy (with some hardy packages, namely libsoup2.4-dev).

When I try to open this webpage:
http://www.circuit-fantasia.com/collections/circuit-collection/menus/circuit-contents.swf
(and click to play)

Firefox quits with sig11 signal.

Here is the backtrace:
lama@arpa:~/.mozilla$ firefox -g
/usr/lib/firefox/run-mozilla.sh -g /usr/lib/firefox/firefox-bin
MOZILLA_FIVE_HOME=/usr/lib/firefox
  LD_LIBRARY_PATH=/usr/lib/firefox:/usr/lib/firefox/plugins:/usr/lib/mre/mre
DISPLAY=:0.0
DYLD_LIBRARY_PATH=/usr/lib/firefox:/usr/lib/mre/mre
     LIBRARY_PATH=/usr/lib/firefox:/usr/lib/firefox/components:/usr/lib/mre/mre
       SHLIB_PATH=/usr/lib/firefox:/usr/lib/mre/mre
          LIBPATH=/usr/lib/firefox:/usr/lib/mre/mre
       ADDON_PATH=/usr/lib/firefox
      MOZ_PROGRAM=/usr/lib/firefox/firefox-bin
      MOZ_TOOLKIT=
        moz_debug=1
     moz_debugger=
/usr/bin/gdb /usr/lib/firefox/firefox-bin -x /tmp/mozargs.J13597
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This GDB was configured as "i486-linux-gnu"...
Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".
(gdb) run
Starting program: /usr/lib/firefox/firefox-bin 
[Thread debugging using libthread_db enabled]
[New process 13600]
[New Thread -1222121792 (LWP 13600)]
[New Thread -1225557104 (LWP 13603)]
[New Thread -1235653744 (LWP 13604)]
[New Thread -1256916080 (LWP 13605)]
[New Thread -1269044336 (LWP 13606)]
[New Thread -1277437040 (LWP 13607)]
[New Thread -1288701040 (LWP 13608)]
[New Thread -1298027632 (LWP 13609)]
[New Thread -1306420336 (LWP 13610)]
[Thread -1306420336 (LWP 13610) exited]
[New Thread -1314813040 (LWP 13611)]
[Thread -1314813040 (LWP 13611) exited]
[New Thread -1314813040 (LWP 13612)]
[New Thread -1306420336 (LWP 13613)]
[New Thread -1323627632 (LWP 13614)]
[Thread -1306420336 (LWP 13613) exited]
[Thread -1323627632 (LWP 13614) exited]
[New Thread -1323627632 (LWP 13615)]
Unsupported movie property name with value "plugin"
Loading stream: http://www.circuit-fantasia.com/collections/circuit-collection/menus/circuit-contents.swf
unhandled event 19
firefox-bin: /build/buildd/libcairo-1.4.10/src/cairo-pen.c:324: _cairo_pen_find_active_cw_vertex_index: Assertion `i < pen->num_vertices' failed.

Program received signal SIGABRT, Aborted.
[Switching to Thread -1222121792 (LWP 13600)]
0xffffe410 in __kernel_vsyscall ()
(gdb) bt
#0  0xffffe410 in __kernel_vsyscall ()
#1  0xb76aaf35 in raise () from /lib/tls/i686/cmov/libc.so.6
#2  0xb76ac8b1 in abort () from /lib/tls/i686/cmov/libc.so.6
#3  0xb76a408e in __assert_fail () from /lib/tls/i686/cmov/libc.so.6
#4  0xb747203f in ?? () from /usr/lib/libcairo.so.2
#5  0xb74c6f0a in ?? () from /usr/lib/libcairo.so.2
#6  0xb74c6edc in ?? () from /usr/lib/libcairo.so.2
#7  0x00000144 in ?? ()
#8  0xb74c6f20 in ?? () from /usr/lib/libcairo.so.2
#9  0xbfca9d40 in ?? ()
#10 0xbfcaa354 in ?? ()
#11 0x09b88a70 in ?? ()
#12 0xb74d0d9c in ?? () from /usr/lib/libcairo.so.2
#13 0x00582214 in ?? ()
#14 0xbfca9e40 in ?? ()
#15 0xbfca9e68 in ?? ()
#16 0xb747077e in ?? () from /usr/lib/libcairo.so.2
#17 0xbfca9f70 in ?? ()
#18 0xbfca9e40 in ?? ()
#19 0xbfca9e48 in ?? ()
#20 0xb747ad65 in ?? () from /usr/lib/libcairo.so.2
#21 0xbfcaa094 in ?? ()
#22 0xbfca9d28 in ?? ()
---Type <return> to continue, or q <return> to quit---
#23 0x00000000 in ?? ()
(gdb) quit
The program is running.  Exit anyway? (y or n) y