The gtk+-2.4.9-backspace.patch (in 2.4.13-10) adds an entry for the backspace signal to the Class struct for GtkEntry and GtkTextView, but doesn't remove a _gtk_reservedN member to compensate for the addition. Thus the class structures for these two widgets are bigger than they should be. After this is fixed, all dependents of gtk2 in the distro should be rebuilt.
After talking to owen, we will have to fix gtk2, then rebuild gtk--, gtksourceview, gedit
This is fixed in the current RHEL4 packages