flexfax: What's "REMOTE HANGUP: DTE to DCE data underflow (code 43)"?

["Kai O'Yang" <oyang@phoebe.fcit.monash.edu.au>]

Hi,

I'm trying to install a Hylafax server on a Solaris 2.5.1 x86 box with
Hayes Accura 288 faxmodem. 

Sometimes sendfax works but a lot of times it dies with:
...
Sep 23 13:16:17.05: [15317]: <-- data [924]
Sep 23 13:16:17.05: [15317]: SENT 25500 bytes of data
Sep 23 13:16:17.05: [15317]: <-- data [2]
Sep 23 13:16:18.37: [15317]: SEND end page
Sep 23 13:16:18.62: [15317]: --> [8:+FHNG:43]
Sep 23 13:16:18.62: [15317]: REMOTE HANGUP: DTE to DCE data underflow (code 43)
Sep 23 13:16:19.24: [15317]: --> [2:OK]
Sep 23 13:16:19.24: [15317]: <-- [5:ATH0\r]
Sep 23 13:16:19.37: [15317]: --> [2:OK]
Sep 23 13:16:19.38: [15317]: SESSION END

Does anyone know what is the problem and how to fix it?

Thanks in advance,
Kai