Hi all,
Many thanks for the solutions you droppped. But my problem seems to be even
much deeper, Maybe a timing problem as Donates said. The LCD that I am strugling now, has a rather simple connections ( P1 is for data and 3 pins of P3 is just for controlling) I also use the busy flag of the LCD which is supposed to be a good avoidance for a likely timing problem. But it still doesn`t work with 55WD.
(The other functionalities of my circuit seem well)

Even worse, my time is shrinking badly, all suggestions are welcome.

Many thanks.

Rustu