"Stuck" Japanese Fleet

[*Lava*]

In my game I have come upon a Japanese naval group consisting of 20+ units including CVs, BBs, DDs, coastal and patrol boats in the open Pacific. I threw them out of Saipan on May 21st where they displaced 6 hexes away. They have been there up to now which is the 27th of August 1944.

Something strange there. They neither move, yet when engaged, were still strong enough to sink one of my CVs.

You can see this here:
http://www.youtube.com/watch?v=PeK24hd5HH4