canon powershot sd600 taking outside blurry pictures.

Ok all my photos of people i take from a distance outside are all blurry. Im not even talking about far maybe 5-15 feet with canon powershot sd600. The thing is i have had this problem the last 3 days before that the pics were good. I would have some blurry but some good ones to. The inside ones are ok. I got my camera last week. I hear a lot about shutter speed.
My friend says the only way on this camera you could change shutter speed is to change the scene mode. The kids and pets mode would give me a faster speed that didn't work though. At the same time though why would i have to adjust the shutter speed when just last week it was working just fine with the same auto mode.
Its only blurry when taking photos of people . I can take pictures of dogs,sky,grass,houses ect..and it looks good. Im taking these blurry pictures with pretty good sunlight out to.

these are the only pics i have right now to show you what i mean.

last week pic looks good
http://i13.photobucket​.com/albums/a265/bay22​4/88.jpg

all pics of people look like this now
http://i13.photobucket​.com …/a265/bay224/IM​G_0399.jpg
http://i13.photobucket​.com/albums/a265/bay22​4/side.jpg
http://i13.photobucket​.com …/a265/bay224/IM​G_0351.jpg

the arm's length self shots look good though for some reason
http://i13.photobucket​.com/albums/a265/bay22​4/44.jpg

Hi there, I looked at the shots but can't get at the exif information that would tell you what shutter speed you're using etc. If you have that type of information, it might help.

Looks to me like a focus issue. It doesnt appear to be motion blur from either the subject or the camera moving, caused by a slow shutter speed. I think it has more to do with the auto focus.

I am not familliar with that camera however. Is there a manual focus or a focus lock? Anything other then the auto focus. Is there anything blocking the auto focus system lamp? Are you half pressing the shutter button to prefocus your pictures, or are you not giving the camera enough time to properly focus the shot. Would dying batteries possibly slow the auto focus time?

Just some suggestions. Hope they help