chord repetition and strings in TabStaff

[Federico Bruni]

q forgets in which string a note is played and as a result you get a
wrong chord in TabStaff:


\version "2.13.49"

\new TabStaff {
  % first chord is ok, second is "wrong"
  <fis a e'\2>4 q
  <e b\2 c'\3 g'>2. q4
}


Is it possible to improve q?
I couldn't find anything related in the open issues of the tracker.

Thanks,
Federico