I went into more boring detail over at the "Black Hole" site in
http://forsu.freeforums.net/thread/9...7s-spawn-issue, but a synopsis:
Looking at the groups in the area there cdrsubron7, the most obvious groups to have DD vessels in them are the Troop Transport groups, with a lot of them set to have 4DD of the same class, whether it'd be Akizuki, Asashio, Shiratsuyu, Mutsuki, or GENERIC. The relation is usually 2 DD per TT ship. Nine of those groups originate in Tokyo, eight of them terminate there, with most of them set to spawn at a 70% rate every several hundred hours (10-12 days). Not suspicious that you would have a bunch of Akizuki coming after you, and it could be that two Troop Transport groups, with 4x Akizuki each could in theory have 2 or 3 from each coming your way. That, however, is not a spawn issue.
There could also be a couple of TF groups, with one outbound and two inbound. They all have calls for GENERIC CL vessels... maybe it is an issue...
The SubHunter groups, Group 074 is suspicious, in that it is set to "Start" on January 1st, 1938, and quit on December 31, 1945. We'll have to change this when we re-do things.
The FastMerchants Group from the Convoys stuff is supposedly not operating at the time of your incident, but might have still been out there finishing up its last run (doubtful). It only has 1x GENERIC DD in it, 2x GENERIC DE, but has a call for a Naka CL. Bunch of Merchant vessels. The other groups in the Convoys stuff would only have GENERIC DD or DE, and between 6 and 10 merchant vessels. You might also see CVE, and/or Seaplane Tenders, and/or TT, etc. in those. Of the "Coastal" stuff, only one group comes close to you, and that has a single Medium Composite Freighter. Maybe one of the ones you sank? The Harbor Traffic doesn't come close to your location...
The Merchants groups are a couple of vessels in each of about potentially 8 groups in the area, with 2 GENERIC freighters, or the one has 2x GENERIC tankers.
I'm stumped. All I can figure is it's a problem with a few little settings being off. The nearest RGG is roughly 35nm from where you are... Nothing sticks out as an obvious culprit.