Crash while typing (could be related to word completion plugin?)

Sometimes Scatch crashes without warning while I'm typing, running in the terminal gives me this output when a crash happens:

[_LOG_LEVEL_WARN 12:07:52.993309] [Gtk] Invalid text buffer iterator: either the iterator is uninitialized, or the characters/pixbufs/widgets in the buffer have been modified since the iterator was created.You must use marks, character numbers, or line numbers to preserve a position across buffer modifications.You can apply tags and insert marks without invalidating your iterators,but any mutation that affects 'indexable' buffer contents (contents that can be referred to by character offset)will invalidate all outstanding iterators
**
Gtk:ERROR:/build/buildd/gtk+3.0-3.4.2/./gtk/gtktextiter.c:2020:_gtk_text_iter_forward_indexable_segment: assertion failed: (gtk_text_iter_starts_line (iter))
Aborted (core dumped)

I'm running the latest Scratch on Ubuntu Precise (package 2.0~r1122-0+pkg47~precise1)

I'm going to switch off the word completion plugin which might be the cuplrit.