It could be a "latency" problem too - where the playback and record are at different times due to the audio latency (delay). However, there isn't much that can be done on most PC sound cards that have a high latency.
The less programs you have running the better off you are with latency. Download and run the DPC Latency Checker and see what that shows for your system.
Click Me for program.
However, bottom line if you can't get the latency down (shorter time) you will just have to continue editing to get the voice in sync with the video. Dose the Sony program have any settings to offset the latency?