Don, VE3HUR, has released a new issue of his Icom IC-765 Notes. It is a very good document gathering much of the information and modifications for the IC-765.
When I ran through the document I realised, that the antenna tuner problem I have been experiencing during the dry-run in December 2004, is actually a common problem. The reason for this behaviour is that the feedback circuit, which controls the tuning motors may become sensitive after a few months of use. The document also describes two ways of curing the problem which is basically a rather easy re-adjustment of the circuit.