R: NULL value passed as symbol address, error in .Call(RS_PostgreSQL_init, config.params, force) :

I'm new to stackoverflow, so please forgive me if this is not the right place for my question.

When I set up a connectin with PostgreSQL via RPostgreSQL package i get the following error:

error in .Call(RS_PostgreSQL_init, config.params, force) :
NULL value passed as symbol address

after performing the following code

con <- dbConnect(dbDriver("PostgreSQL"), dbname = "dbname", host = "xyz0123456", 
                 port = 5432, user = "Username", password ="password")

The code was working on my old machine. but i fails to work on my new PC.

any idea what this is about?

Thanks in advance!

Franz Hans