Installed the SP1b and tryd to make a flight with this bird but notest at CLevel that the birds keep changing directions around the cours of the FMC.Anyone has the same problem?Only at HDG select it keeps a bit the cours selected by me.Thanks on advance for future replys.Geert Burgstra

Give as a screenie of the whole MCP and also the CDU.....It´s not easy for us to guess what you are doing wrong./ Leffe

Sounds like the dreaded 'S' Turn associated with weather program & or FSPUIC. What weather program are you using? Example: Active Sky 2012 Direct Weather Control can cause this type of behaviour with some add on aircrafts autopilots.Incorrect irs alignment can also cause this kind of issue too but I bet it's FSPUIC & weather program.Search forum for 'S Turns' for more help.