GLib-CRITICAL, missing file

[Jorge Villalobos Beato <tiusender gmail com>]

Hi everyone, that's the error I get when running my 
compile-without-problems program:

(myprogram:9483): GLib-CRITICAL **: g_convert_with_fallback: assertion 
`str != NULL' failed

As Murray Cumming suggested me, I've run my program through gdb and this 
is what I have got:

(gdb) run
Starting program: /home/tiusender/Projects/myprogram/src/myprogram
[Thread debugging using libthread_db enabled]
[New Thread -1221683520 (LWP 9483)]

(myprogram:9483): GLib-CRITICAL **: g_convert_with_fallback: assertion 
`str != NULL' failed

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread -1221683520 (LWP 9483)]
0xb78f77a1 in IA__gdk_utf8_to_string_target (str=0x0) at 
gdkselection-x11.c:789
789     gdkselection-x11.c: No such file or directory.
      in gdkselection-x11.c
Current language:  auto; currently c
(gdb)

I guess is something related to gdk (obviously), but it comes with gtk, 
isn't it? Should I reinstall or recompile gtk, glib, gtkmm, glibmm? 
Thanks in advance.