Here my problem I need connect to server on 2000 port its actually manageSIEVE port. Connection setup goes fine SYN->ACK SYN->ACK. When server send me first packet Router thinks its skinny fragmented packet. This packet goes into internal queue and not forwarded of course (wait for other packets I suppose).
In attachment you can find log enabled:
debug ip nat detail
debug ip nat fragments
I don't have command ip nat service skinny - its cisco851 box and yeah I've tried on another box this command doesn't help anyway.