Sent time 1/1/1970 bug
This problem seems to affect some Sony phones (although there is one report of a similar bug with a HTC phone).
If Original timestamps is ticked, some messages may report a sent time of 1/1/1970 or x/x/1969.
This is a bug with the phone's software, not 8sms. The 'sent time' of messages is not correctly stored by the phone and a value of zero is recorded instead (Zero corresponds to the date 1/1/1970).
There are some reports that using Stand-alone mode is a work-around for this problem. In Stand-alone mode, 8sms stores messages and records the 'sent time' value properly.