RefTeX: regular "ding" audio signal

[David Reitter]

RefTeX gives me a regular audio signal, usually a second after the  
point has changed in a buffer in latex-mode.
No message is shown in the echo area or in *Messages*.

I've put a trace on (ding), here is the call stack:

Debugger entered--entering a function:
* ding()
  error("Not on a crossref macro argument")
  reftex-view-crossref(-1 echo)
  byte-code("¬	√=Ƀ≈∆\"Ç	«=Ƀ≈»\"Ǭ)á" [current-prefix-arg  
reftex-auto-view-crossref nil t reftex-view-crossref -1 echo window  
tmp-window] 3)
  reftex-view-crossref-when-idle()
  apply(reftex-view-crossref-when-idle nil)
  byte-code("¡¬H√H\"á" [timer apply 5 6] 4)
  timer-event-handler([t 0 1 199999 t reftex-view-crossref-when-idle  
nil t])


Is there something wrong with my configuration, or is this a bug?

PS.: please cc me on replies.