I was able to sync Plantronics Pro with my N900. But when I am using Bluetooth for calls it becomes unresponsive after a couple of minutes.

My Bluetooth is okay because I used to use it with my old Motorola phone.

Does it have to do something with N900 Bluetooth ???
Anybody else faced the similar issue with Bluetooth handsfree???

bluetooth handsfree works perfect with my car's built-in system...so there's probably not a "universal" issue though there might be a bug specific to certain devices/situations.

I also have problems.
Sometimes the bluetooth connection is lost during a call.
Sometimes there is no sound.
Quite often bluetooth stays connected with my car, although my car and carkit are switched off, but the N900 keeps claiming it is still connected.
Actually it is so unreliable that I have reverted back to my Nokia E90 for calls in my car.

Thats exactly what is happening with me .. mtjioe ...
but it is not car kit it is my Plantronics Pro.