It took me two days of trying, but I fixed the problem. I have the SB behind a Linksys 55AG router and the Linksys is behind an Actiontec router from Verizon (for FIOS, thanks Verizon ;-) ).  I had the remote viewing working until recently, but got a Sonos and we had to tweak the routers and lost it.

 Symptom:  I could watch SB on the internal network AND the setup for external viewing worked.  However, I couldn't watch SB from any remote location. 

Here is what I DIDN'T have to do:

I didn't use the DMZ for either router

I didn't have to factory reset the SB  

I didn't have to change the IP address of the SB, or the port used. 

I had TCP/UDP port forwarding set up for 5001 on the Actiontec to the public IP address of the LS.  I had 5001 on the LS setup for forwarding TCP/UDP to the SB at a fixed IP 192.xxx.x.237.

 So, here is what I needed to do:

1. Even though I had a static IP address setup on the LS, I turned off DCHP completely on the Actiontec.

2. I set the Actiontec firewall to minimum - accept inbound policy.

3. I set the Actiontec to allow UDP traceroute and ICMP pings.

4. I disabled ping rejection and SPI on the LS.

5. This may be the most important thing - and others may have the same issue.  I noticed that the range of IP addresses provided by the DHCP server on the LS did NOT include 237.  It was something like 192.xxx.x.100 - 200  .  I changed this to  100 - 255 and everything worked.  Can't exactly explain why, as it should have screwed up local use of the SB too if there was a problem, but it worked. 

Hope this is helpful to others.

Ps - I have also now given "highest priority" in the LS to the traffic from the SB.  We will see if I get better remote pictures.