Powershot SX240 Disappointing image quality

I hope someone can help as I'm trying to establish if my recently purchased SX240 is faulty.

The problem is as follows:

None of the 150 pictures I have taken seem to be particularly sharp. JPG artifacts are readily visible at 1:1 zoom in Lightroom. There's very little detail in faces - they look very soft/blurred. I have shot in Auto mode where JPG compression is set at the 'fine' resoultion and I have also shot in Program mode with the compression set to 'Superfine' to perform less JPG compression.

Surprisingly it is difficult to tell the difference between a Fine and a Superfine photo.

When reviewing the photos' EXIF data in Breezebrowser, I notice that a lot of the photos show the Subject Distance set to 66m. These photos are mostly of people (family) working in a fairly small back garden which is probably no bigger than 20m x 10m. There are also photos showing a Subject Distance of .55m. In both these situations I would expect the Subject Distance to be 3m to 8m based on where I was focusing, lens zoom etc.

I have the camera set to the following AF settings: AF Frame - centre, AF Frame Size - Normal. Light Metering is set to Evaluative. I have always waited for the focus rectangle to turn green whilst focusing on the area of interest before taking the photo.

The frustrating thing is I've owned a Canon Powershot G5 for 10 years and have not had this soft focus problem. In fact my G5 photos tend to look better at 1:1 and 2:1 zoom than the SX240 photos.

Can anyone help? I feel sure I'm 'driving' the camera correctly. Are there any other settings I need to check? I need to find out if the camera is faulty.

Thanks

Geoff