I found that the problem occurs when:
- Media Player us running
- there are a few other programs running (I start these to test: MDICT, Windows Commander, Papyrus, TCPMP playing)
- the phone is connected to the PC via ActiveSync, OR had previously been connected to the PC (but is now disconnected)
The above is the configuration I use to test. I'm not saying that other config would not cause it to hang but this config will cause it to hang quite predictably. Just wait a while and it will hang. Sometimes, I need to press the keys and it then hang.
I then started to remove the programs from StartUp and test by start them one by one. The culprit is ... O2 Menu.
If I start O2 Menu and use the above config, the phone will hang after a while. But if I don't start O2 Menu, the phone would not hang. I've tested it yesterday overnight and today. So far, if O2 Menu is not running, the phone would not hang.
So now I've stopped using O2 Menu and use something called AbstractStart (which gives me a menu like the Dopod 585 I had previously).
I will continue to monitor this but I'm quite sure it's O2 Menu. The phone would hang quite predictably and now, it didn't hang.
Anyone want to try and report the results here (I might not be monitoring this thread though).