Version 0.8.3 crashes in Ubuntu 12.04 (Gtk and Pango)

[George Fragos]

Crash occures while Ubuntu-Tweak processes the list of old linux headers.
Output of "ubuntu-tweak" follows:

(ubuntu-tweak:5790): GConf-WARNING **: : You can't use a GConfEngine that has an active GConfClient wrapper object. Use GConfClient API instead.
(ubuntu-tweak:5790): GConf-WARNING **: : You can't use a GConfEngine that has an active GConfClient wrapper object. Use GConfClient API instead.
Checking if settings need to be migrated ...no
Checking if internal files need to be migrated ...no
Backend : gconf
Integration : true
Profile : default
Adding plugins
Initializing core options...done

(ubuntu-tweak:5790): Gtk-CRITICAL **: gtk_text_attributes_ref: assertion `values != NULL' failed

(ubuntu-tweak:5790): Gtk-CRITICAL **: gtk_text_attributes_ref: assertion `values != NULL' failed

(ubuntu-tweak:5790): Pango-CRITICAL **: pango_layout_new: assertion `context != NULL' failed
Segmentation fault (segmentation fault) (core dumped)