Ok, here is what I did.
The first career I started with RFB,RSRD and couple of HUD and Sound mods loaded. I started the patrol, sank 3 ships, saving the game numerous times. I took a break and came back a few nights later. I installed the new Gato Graphis mod and tried to load one of my save games. None would load SH4 crashed each time. I then uninstalled the gato graphics mod and tried to load the save games. Same problem, each crashed.
At this point I reloaded the Gato Graphics mod and started a NEW career. Again I made it to the patrol zone and sank 2 ships, saving about 5 times. I took a break and came back a few hours later and tried to load my save games. Same thing, each crashed. I had not changed a thing. VERY frustrating
I then uninstalled ALL mods and just re-installed RFB,RSRD and the Gato Graphics Mod. I started a NEW career and sailed to the patrol zone. I've saved a few times and been able to reload without the game crashing. One of the other mods must have done something to made saving the game ourside of port not possible.
I'll try this for a bit and see what happens.
Kevin