Spacen Jasset reported a problem with doing POST (with data read with a callback) over a proxy when NTLM is used as auth with the proxy. The bug also concerned Digest and was limited to using callback only. Spacen worked with us to provide a useful patch. I added the test case 547 and 548 to verify two variations of POST over proxy with NTLM. 
diff --git a/RELEASE-NOTES b/RELEASE-NOTES index b4cb07d..d69a091 100644 --- a/RELEASE-NOTES +++ b/RELEASE-NOTES 
@@ -33,6 +33,7 @@  buffers  o no longer default-appends ;type= on FTP URLs thru proxies  o SSL session id caching + o POST with callback over proxy requiring NTLM or Digest    This release includes the following known bugs:   @@ -52,6 +53,6 @@    Dan Fandrich, Gisle Vanem, Toby Peterson, Yang Tse, Daniel Black,  Robin Johnson, Michal Marek, Ates Goral, Andres Garcia, Rob Crittenden, - Emil Romanus, Alessandro Vesely, Ray Pekowski + Emil Romanus, Alessandro Vesely, Ray Pekowski, Spacen Jasset    Thanks! (and sorry if I forgot to mention someone)