[Q] Bluetooth headset drops calls

Since upgrading my GT-7000 to the offical OTA Jelly Bean
Android Version 4.1.2
Baseband Version N7000XXLSO
Kernel version 3.0.31-906407 se.infra@SEI-46 #3 SMP PREEMPT Thu Feb 14 02:26:43 KST 2013
Build number JZ)54K.N7000XXLSZ

I lose my bluetooth headset function within calls (it switches back to normal calls, ie I have to hold the phone to my ear)
with my Plantronics PLT_M165 Marque 2 quite often, mostly after about 20-30 seconds.

Has anyone seen similar issues and may have a solution?