at first i need to say sorry for my english which is not that good to describe my problem i think. but i will give my best in hope to get some help here.
i got a mercedes e200 w212 with aps 50 anda nokia n900. i read that though sap profile does not exist calling through bluetooth should work. unfortunately it does not for me and maybe someone here got a clue about what the problem is.
connecting the phone to the aps50 works without any problems. but the moment i try to make a phone call the connection starts to get something like hiccups. i can hear the voice through the speakers of the car but there are lots of hiccups. i mean some words just get lost. the other side can hardly me and most times can not hear me at all. i tried it with my old htc p3600 phone and it works perfectly. but as explained the moment i try it with my n900 handsfree speaking is no longer possible.
please help me out. i searched google as crazy and i tried several german forums where no one could help me.

please help me obi-wan you're my last hope...