[Vala] Memory corruption&coredump on Exit in my first vala program spekle

[Niels Mayer <nielsmayer gmail com>]

Anybody have any ideas on
http://code.google.com/p/spekle/wiki/EvidenceOfMemoryCorruptionOnExit
(warning contains large images,
http://spekle.googlecode.com/svn/wiki/evidence-of-memory-corruption-on-exit.txt
 for error text only).

issue: http://code.google.com/p/spekle/issues/detail?id=1

Summary: after successfully writing a spectrogram image in my first
Vala programming http://spekle.googlecode.com/ (a displayless-version
of
Alexander Kojevnikov's http://www.spek-project.org/ ) I get the
following error, despite not explicitly calling free() out of my Vala
code:

Spekle: saving 'j_s_bach-d_minor_invention.ogg.png'... DONE!
*** glibc detected *** spekle: free(): invalid pointer: 0x00007fa7e05ca010 ***
======= Backtrace: =========
/lib64/libc.so.6[0x3ac0874ac6]
/usr/lib64/libpixman-1.so.0(pixman_image_unref+0x83)[0x3ac9e161b3]
/usr/lib64/libcairo.so.2[0x359c016b85]
/usr/lib64/libcairo.so.2(cairo_surface_finish+0x36)[0x359c02c9d6]
/usr/lib64/libcairo.so.2(cairo_surface_destroy+0x55)[0x359c02ca45]
spekle[0x406b1e]
/lib64/libgobject-2.0.so.0(g_object_unref+0x15f)[0x3ac380da1f]
spekle[0x407d3d]
/lib64/libgobject-2.0.so.0(g_object_unref+0x15f)[0x3ac380da1f]
spekle[0x403857]
/lib64/libc.so.6(__libc_start_main+0xfd)[0x3ac081eb1d]
spekle[0x403439]

The errors seems to occur intermittently, and more often when using
media that is ogg. Retrieving via HTTP seems to reduce the error
potential, but it still happens that way too...

The relevant libraries and compiler I'm using:
vala-0.9.3-1.fc12.x86_64
vala-tools-0.9.3-1.fc12.x86_64
vala-devel-0.9.3-1.fc12.x86_64
libpng-devel-1.2.44-1.fc12.x86_64
libpng-1.2.44-1.fc12.x86_64
gtk2-devel-2.18.9-3.fc12.x86_64
gtk2-2.18.9-3.fc12.x86_64
ffmpeg-0.6-2.fc12.x86_64
ffmpeg-libs-0.6-2.fc12.x86_64
ffmpeg-devel-0.6-2.fc12.x86_64

See http://spekle.googlecode.com/svn/trunk/README for instructions on
obtaining by 'svn' and building on Linux.

Niels
http://nielsmayer.com