On Tue, Apr 19, 2011 at 8:04 PM, Yehavi Bourvine <yehavi.bourvine@gmail.com> wrote:
Hello Michel,
 
  Version 3.1.7 is very old. Try the 3.3.0 version (3.3.1F loses BLF after a while).

You can't do 3.3.1 on the 501 and 601 phones - they are oldies. Polycom has "legacy" firmware for those old phones and you're stuck w/ what they give you, which is indeed 3.1.7. 

-MC