Has anyone gotten AF_LOCAL sockets with SOCK_DGRAM socket protocol working on QNX?

I'm porting a project from Linux to QNX and it contains a library based on exchanging data packets over named sockets.  
It's using SOCK_SEQPACKET which doesn't exist in QNX, so I'm trying to get it to work with minimal changes using 
SOCK_DGRAM.  Everything compiles but I have had various issues:
(1) Clients can send data, but recipient response never arrives.
(2) If I use AF_INET, everything with SOCK_DGRAM works but I'll have to convert the library away from named sockets to 
port numbers.  Not terrible, but not my first choice.
(3) Management doesn't want to leave posix code to use QNX Messages because of future portablity fears.

Before I invest too much time in a dead end, I want to confirm it's not a dead end -- has anyone gotten AF_LOCAL + 
SOCK_DGRAM working in QNX, or knows it's a supported or unsupported combination?

Thank you,
KennF