A2DP on iPhone with P590

Just tried to connect my Plantronics P590 to my iPhone 3G that I updated last week to 3.0.
I am running this for 20 minutes now, and so far I love it in total.
Some points I noticed:

• Quite some bass coming from the P590.
  
• There are some problems, some songs show skipping like an old CD player, and even more enerving is a pitch-down effect (not good for musical ears).I found in some forums that there are indications that this only happens for self-imported tracks and not for iTunes tracks bought on iTunes? I would find this a weird selection effect and would propose that this is caused by differences between mp3 (less efficient) and ac3 (more efficient)?
• Volume control is after pairing with headset blocked on iPhone and solely done via the headset
• With the P590 next and previous track selection does NOT work.
• Even high data rate songs in m4a format (lossless) play nicely via the headset. They /might/ sound a bit better, but that might be wishful thinking as the bluetooth encoder might reduce that quality all away

So overall I am very pleased that this is finally in the iPhone OS, pity that next track does not work with the P590, but I am looking anyway for a new Stereo Bluetooth headset, want to try in-ear plugs this time.