I'm confused about an upgrade

[kylesplanet]

Here's the deal. I have a Porpise class sub. I have just completed my 2nd patrol of my career in Freemantle, it's August 29, 1943. I have had two fantastic patrols with about 70,000 tons to show for it, pretty decent.

Now here comes the confusing part. I was offered an upgrade and took it, it was a Salmon class. The game will not let me add SJ radar, even though it is listed. My Porpise had SJ-i surface radar so I decided to reload my save and not take the upgrade but I get retired if I do so.:stare:

So I guess my question is, is this historically accurate (not being able to get the radar) or a flaw somewhere. My mods are:
P.E.
RFB
RSRDC
Foos Skins
Radio Mods

I have completed all of my objectives so I'm kinda confused :doh:

[1480]

KP, I got bumped up to the DRUM and had the same problem....The radar is available but when I drop and drag it an error message comes up, to the tune of "upgrade not suitable for class" or some type of drivel. I'm in the time frame of June 1942 and the icing on the cake was getting shanghi-ed to Pearl with the new sub...arrrrrrrrrrrrrrrrrrrrrggggggggggggggggghhhhh hhhhhhhhhh!!!!!!!!!:damn:

[Go4It]

I've had similar problem, I saved the game an exited, when I came back to play the next day I was able to get the radar upgrade.

[kylesplanet]

Well I've reloaded several times but its the same thing, I'm not allowed to add the SJ radar to my boat. Kinda hard to believe that it would be historically correct being August 1943 and the fact that I had it on my previous sub. I guess I'll chalk this up to a bug or mistake somewhere and start over.:nope: