Well I can not fix the problem by myself, may I ask for help here.
If anyone would like to test this 10 minutes misson and find out where the problems are ? why destroyers not search for and attack me? Anyone would like to offer me a guidance so that those strange DDs behave as escorts?
you may download this mission here and then test it with IRAI or without IRAI.
http://www.mediafire.com/download.php?olmccgsz86yjyjk
And hope for some constructive advice & guidance thanks!