Truphone-ing to South Africa was a success on the N80i but the quality wasn't as good as my call to Holland. There was no echo but there was a noticeable lag between the time I spoke and the time it was understood at the other end and vice versa.
After the call the N80i "crashed". In quotation marks because the phone still worked but it wouldn't re-acquire my cellphone provider, Fido. Instead of displaying my provider, it displayed nothing (as if the SIM had been deactivated or I was in offline mode).
A bug in the SIP stack on the N80i, a bug in TruPhone, a bug somewhere else in my S60 V3 firmware manifesting itself (I am running V 4.0632.0.38 13-10-2006 RM-92 Nokia N80 (01)) ?
I fixed it by rebooting the phone!