Strange... The PCM3 is my main test device and I paired everything from Windows Mobile HTC Diamond (with WinMob rSAP implementation), to HTC Magic, HTC Desire, Samsung Galaxy S (with Samsung rSAP implementation) and Samsung Nexus S without any problems. The only issue is that it does not recognize phones with "unfixed SDP record". Do you have the "SDP record fix" message? Does the rSAP screen say "SIM access active" when you have the PCM connected?
Prior to 2011 (?) Porsche models there were two different phone modules availble: one supporting HFP only the other rSAP only. As far as I know it was possible to recode the rSAP device to HFP but then loosing rSAP support. The post 2011 PCM rSAP phone module seems to support both HFP and rSAP.