Silly stuff this, I just discovered that another bug that was in 4.10m and was fixed in 4.10.1m is present in UP3 RC3 (maybe in RC1 and RC2 as well)
It's the one when in a coop a static ship is being hit and sinking, after it sank completely, it simply re-spawns.
Found this while looking at the Pearl Harbor alternative mission, the Japanese do sink them battleships, and the USA do sink a carrier, but if you let it run long enough, battle ship row looks like nothing ever happened there, and the Blue Carrier is happily sailing along again...
As for that PH alternative mission that failed to work in 4.10.1m, I found out it had an invalid height for the second waypoint of the F4F3's (0m).
Fixed that, so we can still use it some other time )
(BTW, that PHA mission with the waypoint error in it does run fine on UP3 RC3, no issue there... This stuff is now very close to make me go crazy)